Prosecution Insights
Last updated: October 04, 2026
Application No. 18/260,172

SYSTEMS AND METHODS FOR FIBER OPTIC FOURIER SPECTROMETRY MEASUREMENT

Final Rejection §103§112
Filed
Feb 13, 2024
Priority
Jan 06, 2021 — provisional 63/134,573 +4 more
Examiner
CARLSON, JOSHUA MICHAEL
Art Unit
2877
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Sentek Instrument LLC
OA Round
2 (Final)
59%
Grant Probability
Moderate
3-4
OA Rounds
2m
Est. Remaining
99%
With Interview

Examiner Intelligence

Grants 59% of resolved cases
59%
Career Allowance Rate
52 granted / 88 resolved
-8.9% vs TC avg
Strong +40% interview lift
Without
With
+39.5%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
31 currently pending
Career history
122
Total Applications
across all art units

Statute-Specific Performance

§101
1.6%
-38.4% vs TC avg
§103
54.7%
+14.7% vs TC avg
§102
10.0%
-30.0% vs TC avg
§112
29.5%
-10.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 88 resolved cases

Office Action

§103 §112
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Response to Amendment and Status of Application This notice is in response to the amendments filed 10 June 2026. Claims 1-35 are pending in the instant application where claims 10, 13, 15-20, 30, and 32-35 are withdrawn due to a restriction/election of species requirement and claims 1, 4, 6-8, 21, 24, 26-28 have been amended. Applicant’s amendments to the claims have overcome most objections and rejections under 35 U.S.C. 112(b) set forth in the Non-Final Office Action dated 23 March 2026. Those objections and rejections overcome are hereby withdrawn. Examiner notes there being newly added limitations within claim 1 that are not indicated as newly added – this includes the last two lines of claim 1 page 1 and the first line of claim 1 page 2 up until “phase”. Examiner also notes that the “Application Serial Number” header is incorrect within the claims – it recites 17/609,542 rather than 18/260,172. Response to Arguments Applicant's arguments filed 10 June 2026 have been fully considered but they are not persuasive. Regarding applicant’s argument with respect to claims 4 and 24 and the relative term rejection under 35 U.S.C. 112(b), applicant points to page 36 as evidence that one of ordinary skill in the art would understand the term “similar”. However, the passage of claim 36 recites “similar in this context is defined as the difference between the sensor OPD and the TMI OPD to be comparable to or smaller than Lc”, which recites the coherence length of the light source Lc. The claim makes no comparison to the coherence length of the light source with respect to the hollow cavity optical path distance or the optical path difference, and cannot be considered as providing a means for a PHOSITA to determine the metes and bounds associated with similar in the context of claims 4 and 24. For this reason, the rejection under 35 U.S.C. 112(b) is maintained below. Regarding applicant’s arguments (remarks page 6 paragraph 1 – page 7 paragraph 2) that because the reference Kempen recites a reference mirror MR along with the test mirror assembly 35 which generates interferograms, the modification of Islam removes this mechanism and “creates a fundamental change in the principle of Kempen’s operation. Examiner disagrees, as there is no suggestion within the office action to replace the reference mirror MR with the Michelson interferometer of Islam. The test mirror assembly 35 of Kempen is analogous to the Fabry-Perot fiber sensor disclosed in Islam. The modification of Kempen leaves the reference mirror unchanged, and instead replaces the photodetector 16 mechanism with a secondary interferometer, where the secondary interferometer ultimately possesses a photodetector mechanism. Given the maintenance of the principle of Kempen’s operation (i.e. obtaining interferograms between a test mirror and reference mirror via a photodetection apparatus), one would not consider the combination to violate the guidelines set forth in MPEP §2143.01 VI. As the reference mirror MR of Kempen is left unmodified, applicant’s assertions that the modification of Kempen with Islam renders Kempen unfit for its intended purpose are found as unpersuasive. Regarding applicant’s arguments (remarks page 8 paragraph 3 – page 9 paragraph 1) which argues that because the distance traveled by the mirror controlled by motorized stage of Islam is not appreciably more than 6.8 µm (a point which examiner does necessarily concede) and because the reference mirror of Kempen is controlled by use of a stepper motor, that the stepper motor must move an order of magnitude more than the distance traveled by the motorized stage of Islam. Examiner finds this argument unpersuasive for multiple reasons – firstly, as indicated in the previous paragraph, there is no indication in the rejection that the reference mirror of Kempen is being replaced by either the PZT arm or motorized stage of Islam; therefore, there is consequence of the stepper motor of Kempen traveling appreciably more than 6.8 µm. Secondly, there is no suggestion that the stepper motor of Kempen necessarily results in a traversed distance an order of magnitude greater than 6.8 µm – Kempen only recites that the scanning of the reference mirror is accomplished through the use of a stepper motor or other high precision mechanical device. For both of these reasons, examiner finds applicant’s arguments unpersuasive. Drawings Replacement sheets for figures 2 and 4 were received on 10 June 2026 to correct figure numbering and remove errant labeling, some of which do not appear in the specification (i.e. 216A-216C). These drawings are accepted. Specification The lengthy specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification. Aside from the objection below, the other amendments to the specification filed 10 June 2026 contain no new matter and are hereby entered. The disclosure is objected to because of the following informalities: Within the amended specification on page 15, line 26 recites “the second arm 210 is labeled “DTS” on Fig. 1 and will be alternatively referenced…”. However, the second arm 210 labeled DTS does not appear in figure 1 and instead appears in figures 2 and 4. Appropriate correction is required. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 4-9, 24-26, and 28-29 rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Regarding claim 4, the term “similar” within “optical path difference that is equal to or similar to the hollow cavity optical path distance” on lines 10-11 is a relative term which renders the claim indefinite. The term “similar” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Neither the specification nor the claim provides a means to ascertain how close the optical path difference should be to the hollow cavity optical path distance to be considered “similar to”. Examiner will interpret the limitation such that the optical path difference being within a scalar multiple of the hollow cavity optical path difference will read on the claim. Regarding claim 24, the term “similar” within “optical path difference that is equal to or similar to the hollow cavity optical path distance” on line 9 is a relative term which renders the claim indefinite. The term “similar” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Neither the specification nor the claim provides a means to ascertain how close the optical path difference should be to the hollow cavity optical path distance to be considered “similar to”. Examiner will interpret the limitation such that the optical path difference being within a scalar multiple of the hollow cavity optical path difference will read on the claim. Claims 5-9 are rejected due to their dependence on the deficiencies of claim 4. Claims 25-26 and 28-29 are rejected due to their dependence on the deficiencies of claim 24. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1-3, 21-23, and 27 are rejected under 35 U.S.C. 103 as being unpatentable over 6,014,215 A by Lothar U. Kempen et al. (herein after “Kempen”) in view of “Chronology of Fabry-Perot Interferometer Fiber-Optic Sensors and Their Applications: A Review” by Md. Rajibul Islam et al. (doi:10.3390/s140407451) (herein after “Islam”), and further in view of US 2020/0386583 A1 by Mahmoud Farhadiroushan et al. (herein after “Mahmoud”). Regarding claim 1, Kempen discloses a method for measuring at least pressure, acceleration, strain, or temperature (Kempen col. 1 ll. 21-26 discloses parameter measurements of fluid pressure), comprising: injecting a light in a manner providing the light, as an injected light, successive incidence with a sensor first reflecting surface and a sensor second reflecting surface (Kempen fig. 1 and col 3 ll. 45-57 and col 4 ll. 13-15, 46-50 disclose a fiber optic sensor system 10 discloses an illumination source 12 which transmits light to an optical coupler 24 and is directed to a test mirror assembly 35; test mirror assembly comprises two reflecting surfaces M1 and M2 [sensor first reflecting surface and sensor second reflecting surfaces respectively]; col 5 ll. 32-33 discloses an activation of light source and a continuous scanning procedure with the light source activated [injecting a light providing successive incidence]) supported by structure configured to change, responsive to changes in the pressure, acceleration, strain, or temperature, or combinations or sub-combinations thereof (Kempen col 3 ll. 45-57 discloses interferometric fiber optic sensor system 10 of fig. 1 adapted to measure pressure [responsive to changes in pressure, acceleration, strain, temperature or combinations/subcombinations thereof]), a sensor optical path distance of a sensor optical path between the sensor first reflecting surface and the sensor second reflecting surface (Kempen col. 6 ll. 30-39 and figs. 1 and 4 disclose an optical path length difference x between M1 and M2 due to pressure applied to M2 [x being a change in sensor optical path difference between first and second reflecting surfaces]), receiving sensor reflections, comprising reflections of the injected light from the sensor first reflecting surface, and reflections of the injected light from the sensor second reflecting surface (Kempen figs. 1 and col. 5 ll. 6-13 disclose that light reflected from mirrors M1 and M2 are transmitted to coupler 24 [received sensor reflections]), and computerized measuring of the pressure, acceleration, strain, or temperature, or combinations or sub-combinations thereof, including computerized detection of changes in the sensor optical path difference (Kempen fig. 1 and col 5 ll. 16-25 discloses a signal processing unit 18 which obtains reflected signals from M-1 and M2 as output from photodetector to determine pressure P applied to the system; signal processing unit 18 may be a computer [computerized measuring of pressure]; col 6 equation 1 discloses the change of sensor optical path difference, and equations 2-3 relate the optical path difference to the pressure applied to the mirror M2 [computerized detection of changes in the sensor optical path difference]) Kempen is silent to routing the sensor reflections, as routed sensor reflections, to an interferometer that includes a first optical path and a second optical path, the first optical path having a first optical path fixed length, starting at a first optical path start and ending at a first reflector, and the second optical path having a second optical path length, starting at a second optical path start and ending at a second reflector; propagating the routed sensor reflections within the interferometer, the propagating comprising: propagating a first portion of the routed sensor reflections along the first optical path to incidence with the first reflector, propagating a second portion of the routed sensor reflections along the second optical path to incidence with the second reflector, propagating first reflector reflections of the first portion of the routed sensor reflections, along the first optical path, to the first optical path start, and propagating second reflector reflections of the second portion of the routed sensor reflections, along the second optical path, to the second optical path start; and receiving a combination comprising, from the first optical path start the first reflector reflections of the first portion of the routed sensor reflections and from the second optical path start the second reflector reflections of the first portion of the routed sensor reflections. However, Islam does address this limitation. Kempen and Islam are considered to be analogous to the present invention because they relate to interferometric sensors measuring either temperature, pressure, or strain. Islam discloses “routing the sensor reflections, as routed sensor reflections, to an interferometer that includes a first optical path and a second optical path, the first optical path having a first optical path fixed length, starting at a first optical path start and ending at a first reflector, and the second optical path having a second optical path length, starting at a second optical path start and ending at a second reflector” (Islam section 2.1.1 (pg. 7454-7455) and fig. 1 disclose a cavity Fabry-Perot fiber sensor comprising a glass tube with an air gap, core, and cladding appears coupled to an LED [cavity Fabry-Perot fiber is equivalent to the two mirrors M--1 and M2 of Kempen]; light reflected by surfaces surrounding the air gap are routed to Michelson interferometer at the top left quadrant of the figure, where a beam splitter BS splits the optical path into optical paths comprising mirrors at each end [mirror w/ PZT at one end is considered the first reflector and mirror with motorized stage is considered the second reflector – PZT leg is fixed compared with the motorized stage leg, which shows the ability to change its path length]; each leg to the respective mirror comprises a respective optical path length [first and second optical path lengths], the starting points of which are considered at the beam splitter and ending at the respective mirrors); and “propagating the sensor reflections within the interferometer, the propagating comprising: propagating a first portion of the routed sensor reflections along the first optical path to incidence with the first reflector” (Islam fig. 1; light split by beam splitter BS is incident to mirror w/ PZT [propagating a first portion of the sensor reflections along first optical path to incidence with first reflector]), “propagating a second portion of the routed sensor reflections along the second optical path to incidence with the second reflector” (Islam fig. 1; other portion of light split by beam splitter BS is incident to mirror w/ motorized stage [propagating a second portion of the sensor reflections along second optical path to incidence with second reflector]), “propagating first reflector reflections of the first portion of the routed sensor reflections, along the first optical path, to the first optical path start” (Islam fig. 1; once light is reflected at mirror w/ PZT, it returns along first optical path to first optical path start), and “propagating second reflector reflections of the second portion of the routed sensor reflections, along the second optical path, to the second optical path start” (Islam fig. 1; once light is reflected at mirror w/ motorized stage it returns along second optical path to second optical path start); and “receiving a combination comprising, from the first optical path start the first reflector reflections of the first portion of the routed sensor reflections and from the second optical path start the second reflector reflections of the first portion of the routed sensor reflections” (Islam fig. 1 and caption discloses photodiode which receives which receives signals from both arms of the interferometer, including the first reflector reflections of the first portion of routed sensor reflections and the second reflector reflections of the first portion of the routed sensor reflections). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen to incorporate routing the sensor reflections, as routed sensor reflections, to an interferometer that includes a first optical path and a second optical path, the first optical path having a first optical path fixed length, starting at a first optical path start and ending at a first reflector, and the second optical path having a second optical path length, starting at a second optical path start and ending at a second reflector and propagating the sensor reflections within the interferometer, the propagating comprising: propagating a first portion of the routed sensor reflections along the first optical path to incidence with the first reflector, propagating a second portion of the routed sensor reflections along the second optical path to incidence with the second reflector, propagating first reflector reflections of the first portion of the routed sensor reflections, along the first optical path, to the first optical path start, and propagating second reflector reflections of the second portion of the routed sensor reflections, along the second optical path, to the second optical path start and receiving a combination comprising, from the first optical path start the first reflector reflections of the first portion of the routed sensor reflections and from the second optical path start the second reflector reflections of the first portion of the routed sensor reflections as suggested by Islam for the advantage of enabling the detection of pressure deflection while enabling the use of an LED light as a light source, serving as an economical light source option (i.e. reducing cost of the interferometer) (Islam page 7455, section 2.1.2, ll. 1-8). Kempen when modified by Islam is silent to phase shifting splitting a combination of the first reflector reflections of the first portion of the routed sensor reflections and the second reflector reflections of the second portion of the routed sensor reflections into separate channel signals, comprising first channel signals, second channel signals, and third channel signals, mutually spaced from another with respect to phase; and computerized measuring of the pressure, acceleration, strain, or temperature, or combinations or sub-combinations thereof, including computerized detecting of changes in the sensor optical path difference, based on the first channel signals, second channel signals, and third channel signals. However, Mahmoud does address these limitations. Kempen, Islam, and Mahmoud are considered to be analogous to the present invention because they are interferometric sensors measuring either temperature, pressure, or strain. Mahmoud discloses “phase shifting splitting a combination of the first reflector reflections of the first portion of the sensor reflections and the second reflector reflections of the second portion of the sensor reflections into separate channel signals, comprising first channel signals, second channel signals, and third channel signals, mutually spaced from another with respect to phase” (Mahmoud fig. 1 and [0049]-[0050] generally disclose an interferometer for measuring amplitude, phase, frequency of an optical signal, i.e. an optical signal received from sensor first reflecting surface and sensor second reflecting surface; three photodetectors 112 [first channel], 113 [second channel], and 114 [third channel] measure intensity of interference signal components from the interferometer [first, second, and third channel signals], where optical coupler 104 imparts relative phase shifts of 0°, -120°, and +120° [mutually spaced from another with respect to phase]); and “computerized measuring of the pressure, acceleration, strain, or temperature, or combinations or sub-combinations thereof, including computerized detecting of changes in the sensor optical path difference, based on the first channel signals, second channel signals, and third channel signals” (Mahmoud fig. 7 shows outputs of photodetectors 112, 113, 114 input to processor unit 714 [computer]; [0166] discloses that the sensor system [i.e. at least partial outputs of photodetectors 112, 113, and 114 to processor unit of fig. 7] are used within a temperature sensor system, or any other sensed parameter that perturbs the path length of the optical fiber [any other sensed parameter here includes pressure, where pressure has been detectable within both Kempen and Islam]; parameter is sensed based on perturbed path length of optical fiber [computerized detecting of changes in optical path difference]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen and Islam to incorporate phase shifting splitting a combination of the first reflector reflections of the first portion of the routed sensor reflections and the second reflector reflections of the second portion of the routed sensor reflections into separate channel signals, comprising first channel signals, second channel signals, and third channel signals, mutually spaced from another with respect to phase; and computerized measuring of the pressure, acceleration, strain, or temperature, or combinations or sub-combinations thereof, including computerized detecting of changes in the sensor optical path difference, based on the first channel signals, second channel signals, and third channel signals as suggested by Mahmoud for the advantage of improving signal visibility and sensitivity by utilizing the multiple samples of the photodetector outputs (Mahmoud [0057]). Regarding claim 2, Kempen when modified by Islam and Mahmoud discloses the method of claim 1. Kempen when modified by Islam are silent to the method of claim 1, wherein the phase shift distributing is configured to space the first channel signals, second channel signals, and third channel signals uniformly by 120 degrees. However, Mahmoud does address this limitation. Mahmoud discloses the method of claim 1, “wherein the phase shift distributing is configured to space the first channel signals, second channel signals, and third channel signals uniformly by 120 degrees” (Mahmoud [0049] discloses that optical coupler 104 introduces relative phase shifts of 0°, -120°, and +120° [space first, second, third channel signals uniformly by 120 degrees]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen in view of Islam to incorporate wherein the phase shift distributing is configured to space the first channel signals, second channel signals, and third channel signals uniformly by 120 degrees as suggested by Mahmoud for the advantage of improving signal visibility and sensitivity by utilizing the multiple samples of the photodetector outputs (Mahmoud [0057]). Regarding claim 3, Kempen when modified by Islam and Mahmoud discloses the method of claim 1, and Kempen further teaches the method wherein the computerized measuring of the pressure, acceleration, strain, or temperature, or combinations or sub-combinations thereof is configured to perform dynamic measuring of a pressure, acceleration, strain, or temperature on the sensor cavity body (Kempen col 10 ll. 65-67 discloses that the pressure sensor enables high precision at the same time having a large dynamic range [pressure detectable via dynamic measuring]; additionally, intensity of signal detected by photodetector is shown in fig. 3 as a function of time – the steps of fig. 2 are repeatable and therefore a dynamic pressure measurement is enabled by repeating the steps of fig. 2). Regarding claim 21, Kempen discloses a system for measuring at least pressure, acceleration, strain, or temperature (Kempen col. 1 ll. 21-26 discloses parameter measurements of fluid pressure), comprising: a sensor cavity body, configured to receive an injected light and to provide an injection light optical path for the injected light that includes a hollow cavity first facing surface facing a hollow cavity and, spaced by a hollow cavity optical path distance from and facing toward the hollow cavity first facing surface, a hollow cavity second facing surface (Kempen fig. 1 and col 3 ll. 45-57 and col 4 ll. 13-15, 46-50 disclose a fiber optic sensor system 10 discloses an illumination source 12 which transmits light to an optical coupler 24 and is directed to a test mirror assembly 35; test mirror assembly comprises two reflecting surfaces M1 and M2 separated by optical path length x [sensor first reflecting surface and sensor second reflecting surfaces respectively, wherein the hollow cavity second facing surface is spaced by hollow cavity optical path distance and faces toward the hollow cavity first facing surface]; col 5 ll. 32-33 discloses an activation of light source and a continuous scanning procedure with the light source activated [injecting a light providing successive incidence]), and configured such that changes in a force produce changes in the hollow cavity optical path distance between the hollow cavity first facing surface and the hollow cavity second facing surface (Kempen col 3 ll. 45-57 discloses interferometric fiber optic sensor system 10 of fig. 1 adapted to measure pressure [responsive to changes in pressure, acceleration, strain, temperature or combinations/subcombinations thereof]; col. 6 ll. 30-39 and figs. 1 and 4 disclose an optical path length x between M1 and M2 which changes due to pressure applied to M2 [x changing being indicative of a change in sensor optical path difference between first and second reflecting surfaces], see equation (1) for the difference in path lengths due to a pressure applied) a splitter-router (Kempen fig. 1 and col 3 ll. 58 – col 4 ll. 2 discloses an optical coupler 24 [splitter-router]), configured to: receive, as a sourced light, a light from a light source (Kempen fig. 1 and col. 3 ll. 58 – col 4 ll. 2 discloses illumination source 12 which emits light directed to optical coupler), route the sourced light as the injected light, over an optical fiber to the sensor cavity body (Kempen fig. 1 and col. 3 ll. 58 – col. 4 ll. 2 discloses the illumination source 12 coupled to test mirror assembly 35 [route sourced light via optical coupler 24 to sensor cavity body 35]), receive from the sensor cavity body, cavity body reflection signals, which are responsive to the injected light and comprise hollow cavity first reflection signals from the hollow cavity first facing surface and hollow cavity second reflection signals from the hollow cavity second facing surface (Kempen figs. 1 and col. 5 ll. 6-13 disclose that light reflected from mirrors M1 and M2 [having been emitted by illumination source 12 to the test cavity 35] are transmitted back to optical coupler 24 [received sensor reflections]; mirrors M-1 and M2 reflect hollow cavity first reflection signals and hollow cavity second reflection signals, respectively), and route at least a portion of the cavity body reflection signals as routed cavity body reflection signals (Kempen fig. 1 and col 5 ll. 6-13 disclose light reflected from mirrors M1 and M2 are transmitted back to optical coupler 24; light routed via the optical coupler 24 from the mirrors are considered routed cavity body reflection signals); and a computer implemented dynamic measuring logic, comprising a processor coupled to a data memory and an instruction memory, the instruction memory storing processor executable instructions that cause the processor to perform a dynamic measuring to detect changes in the hollow cavity optical path distance (Kempen fig. 1 and col 5 ll. 16-25 disclose signals obtained by a signal processing unit 18 [at least routed cavity body reflection signals], where the signal processing unit 18 is one of a digital signal processor or a computer; one of ordinary skill in the art recognizes a computer as containing a processor coupled to data memory and instruction memory, executing stored instructions to cause the processor to perform a task; the signal processing unit 18 determines a magnitude of pressure P applied to a transducer surface 20 [the pressure applied to transducer surface 20 changes the optical path length between M1 and M2 [changes in the hollow cavity optical path distance], again, see equation 1]; “dynamic measuring” taught by Kempen as it teaches detecting the change in the hollow cavity optical path distance rather than only obtaining a static measurement). Kempen is silent to routing at least a portion of cavity body reflection signals to an interferometer input as routed cavity body reflection signals; an interferometer, configured to: receive via the interferometer input the routed cavity body reflection signals, propagate the routed cavity body reflection signals such that a first portion of the routed cavity body reflection signals arrives, via a first optical path, at a first reflector and a second portion of the routed cavity body reflection signals arrives, via a second optical path, at a second reflector, and reflect from the first reflector a portion of the routed cavity body reflection signals, as interferometer first reflector signals, and reflect from the second reflector of another portion of the routed cavity body reflection signals, as interferometer second reflector signals. However, Islam does address these limitations. Kempen and Islam are considered to be analogous to the present invention because they relate to interferometric sensors measuring either temperature, pressure, or strain. Islam discloses “routing at least a portion of cavity body reflection signals to an interferometer input as routed cavity body reflection signals; an interferometer” (Islam section 2.1.1 (pg. 7454-7455) and fig. 1 disclose Michelson interferometer, where signals from a fiber Fabry-Perot cavity comprising glass tube with air gap, core, and cladding coupled to an LED [analogous to the test mirror assembly 35 of Kempen]; light reflected by surfaces surrounding the air gap are routed to Michelson interferometer at the top left quadrant of the figure [routing at least portion of cavity body reflection signals to an interferometer input]) configured to: receive via the interferometer input the routed cavity body reflection signals” (Islam section 2.1.1 (pg. 7454-7455) and fig. 1 show the Michelson interferometer receiving routed cavity body reflection signals from fiber Fabry-Perot cavity), “propagate the routed cavity body reflection signals such that a first portion of the routed cavity body reflection signals arrives, via a first optical path, at a first reflector and a second portion of the routed cavity body reflection signals arrives, via a second optical path, at a second reflector” (Islam section 2.1.1 (pg. 7454-7455) discloses that the Michelson type interferometer where a beam splitter BS splits the routed cavity body reflection signals following the routed optical path into optical paths comprising mirrors at each end [mirror w/ PZT at one end is considered the first reflector and mirror with motorized stage is considered the second reflector]; each leg to the respective mirror represent a respective optical path [first and second optical paths]), and reflect from the first reflector a portion of the routed cavity body reflection signals, as interferometer first reflector signals, and reflect from the second reflector of another portion of the routed cavity body reflection signals, as interferometer second reflector signals” (Islam fig. 1; the light incident to the mirror w/ PZT is reflected as interferometer first reflector signals and light incident to the mirror w/ motorized stage is reflected as interferometer second reflector signals). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen to incorporate routing at least a portion of cavity body reflection signals to an interferometer input as routed cavity body reflection signals; an interferometer, configured to: receive via the interferometer input the routed cavity body reflection signals, propagate the routed cavity body reflection signals such that a first portion of the routed cavity body reflection signals arrives, via a first optical path, at a first reflector and a second portion of the routed cavity body reflection signals arrives, via a second optical path, at a second reflector, and reflect from the first reflector a portion of the routed cavity body reflection signals, as interferometer first reflector signals, and reflect from the second reflector of another portion of the routed cavity body reflection signals, as interferometer second reflector signals as suggested by Islam for the advantage of enabling the detection of pressure deflection while enabling the use of an LED light as a light source, serving as an economical light source option (i.e. reducing cost of the interferometer) (Islam page 7455, section 2.1.2, ll. 1-8). Kempen when modified by Islam is silent to a phase shifting splitter, configured to: receive and combine, into interferometer reflector signals, the interferometer first reflector signals and the interferometer second reflector signals, separate the interferometer reflector signals into separate channel signals, comprising first channel signals, second channel signals, and third channel signals, mutually spaced from one another with respect to phase, and a computer implemented dynamic measuring logic comprising a processor to detect changes in the hollow cavity optical path distance based on the first channel signals, second channel signals, and third channel signals. However, Mahmoud does address this limitation. Kempen, Islam, and Mahmoud are considered to be analogous to the present invention because they are interferometric sensors measuring either temperature, pressure, or strain. Mahmoud discloses “a phase shifting splitter (Mahmoud fig. 1 and [0049]-[0050] discloses an optical coupler 104 imparting relative phase shifts [phase shifting splitter]), configured to: “receive and combine, into interferometer reflector signals, the interferometer first reflector signals and the interferometer second reflector signals” (Mahmoud fig. 1 and [0049]-[0050] generally disclose an interferometer for measuring amplitude, phase, frequency of an optical signal, i.e. interferometer first and second reflector signals), “separate the interferometer reflector signals into separate channel signals, comprising first channel signals, second channel signals, and third channel signals, mutually spaced from one another with respect to phase” (Mahmoud fig. 1 and [0049]-[0050] disclose three photodetectors 112 [first channel], 113 [second channel], and 114 [third channel] measure intensity of interference signal components [interferometer reflector signals] from the interferometer [separate into first, second, and third channel signals], where optical coupler 104 imparts relative phase shifts of 0°, -120°, and +120° [mutually spaced from another with respect to phase]), and “a computer implemented dynamic measuring logic comprising a processor to detect changes in the hollow cavity optical path distance based on the first channel signals, second channel signals, and third channel signals” (Mahmoud fig. 7 shows outputs of photodetectors 112, 113, 114 input to processor unit 714 [computer]; [0166] discloses that the sensor system [i.e. at least partial outputs of photodetectors 112, 113, and 114 to processor unit of fig. 7] are used within a temperature sensor system, or any other sensed parameter that perturbs the path length of the optical fiber [any other sensed parameter here includes pressure, where pressure has been detectable within both Kempen and Islam]; parameter is sensed based on perturbed path length of optical fiber [computerized detecting of changes in optical path difference based on first, second, and third channels]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen in view of Islam to incorporate a phase shifting splitter, configured to: receive and combine, into interferometer reflector signals, the interferometer first reflector signals and the interferometer second reflector signals, separate the interferometer reflector signals into separate channel signals, comprising first channel signals, second channel signals, and third channel signals, mutually spaced from one another with respect to phase, and a computer implemented dynamic measuring logic comprising a processor to detect changes in the hollow cavity optical path distance based on the first channel signals, second channel signals, and third channel signals as suggested by Mahmoud for the advantage of improving signal visibility and sensitivity by utilizing the multiple samples of the photodetector outputs (Mahmoud [0057]). Regarding claim 22, Kempen when modified by Islam and Mahmoud discloses the system of claim 21. Kempen when modified by Islam is silent to the system of claim 21, wherein the phase shifting splitter is further configured to space the first channel signals, second channel signals, and third channel signals uniformly by 120 degrees. However, Mahmoud does address this limitation. Mahmoud discloses the system of claim 21, “wherein the phase shifting splitter is further configured to space the first channel signals, second channel signals, and third channel signals uniformly by 120 degrees” (Mahmoud [0049] discloses that optical coupler 104 introduces relative phase shifts of 0°, -120°, and +120° [space first, second, third channel signals uniformly by 120 degrees]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen in view of Islam to incorporate wherein the phase shifting splitter is further configured to space the first channel signals, second channel signals, and third channel signals uniformly by 120 degrees as suggested by Mahmoud for the advantage of improving signal visibility and sensitivity by utilizing the multiple samples of the photodetector outputs (Mahmoud [0057]). Regarding claim 23, Kempen when modified by Islam and Mahmoud discloses the system of claim 21, and Kempen further teaches the system wherein the computer implemented dynamic measuring logic is further configured to perform the dynamic measuring of a pressure or acceleration on the sensor cavity body (Kempen col 10 ll. 65-67 discloses that the pressure sensor enables high precision at the same time having a large dynamic range [pressure detectable via dynamic measuring]; additionally, intensity of signal detected by photodetector is shown in fig. 3 as a function of time – the steps of fig. 2 are repeatable and therefore a dynamic pressure measurement is enabled by repeating the steps of fig. 2). Regarding claim 27, Kempen when modified by Islam and Mahmoud discloses the system of claim 21, and Kempen further teaches the system further comprising: a tapping logic, configured to tap a portion of the cavity body reflection signals, as tapped sensor reflection signals (Kempen figs 2-3 and col 10 ll. 26-31 discloses the process by which the pressure applied to mirror M2 is obtained – the signals used during the calculation of pressure are considered a “tapped portion” of the sensor reflection signals, consistent with the broadest reasonable interpretation of the claim; the computer serving as the signal processing unit 18 therefore contains the claimed tapping logic, since the computer is “configured to tap a portion of the sensor reflection signals”); and a computer implemented logic for performing a computerized absolute measuring of the pressure, acceleration, strain, or temperature comprising computerized absolute measuring of changes in the hollow cavity optical path distance, based on the tapped sensor reflection signals (Kempen col. 10 ll. 55-60 discloses that the pressure sensor system allows for absolute measurements of the position of the test mirror [absolute measuring of the hollow cavity optical path difference]; col. 5 ll. 16-25 discloses the computerized measurement of the pressure P applied to the transducer surface 20 [where measuring pressure is dependent on measuring the hollow cavity optical path difference]). Claims 4-5, 7, and 24-25 are rejected under 35 U.S.C. 103 as being unpatentable over Kempen in view of Islam, in view of Mahmoud, and further in view of US 5,47,323 A by Jeffery P. Andrews et al. (herein after “Andrews”). Regarding claim 4, Kempen when modified by Islam and Mahmoud discloses the method of claim 1, and Kempen further teaches the method wherein: the sensor first reflecting surface comprises a hollow cavity first facing surface, which is an interface between a surface of a cylinder base and a hollow cavity formed in the cylinder base; the sensor second reflecting surface comprises a hollow cavity second facing surface, which is an interface between the hollow cavity and a surface of a cap that is attached to the cylinder base; the hollow cavity first facing surface is spaced from the hollow cavity second facing surface by a hollow cavity optical path distance (Kempen figs 4-5 and col. 7 ll. 1-32 disclose the first reflecting surface M1 appears between one an outer surface of flange 56 [surface of cylindrical base] and hollow cavity denoted by x; the second reflecting surface M2 appears between the hollow cavity denoted by x and an outer ring seal 60b [cap]; outer ring seal 60b is shown connected to pipe 50, where the pipe 50 coupled with flange 56 is considered as the cylinder base [second reflecting surface an interface between hollow cavity and surface of cap attached to cylinder base]; M1 and M2 are separated by a distance [hollow cavity optical path distance]; fig. 5 shows that the components are cylindrical in nature, and the mirrors are concentric with one another; pipe 50 is shown as circular in fig. 5, i.e. cylindrical going into the page). Kempen when modified by Islam and Mahmoud is silent to the method of claim 1, wherein the second optical path length differs from the first optical path length by an optical path difference that is equal to or similar to the hollow cavity optical path distance. However, Andrews does address this limitation. Kempen, Islam, Mahmoud, and Andrews are considered to be analogous to the present invention because they are interferometric sensors measuring either temperature, pressure, or strain. Andrews discloses the method of claim 1, “wherein the second optical path length differs from the first optical path length by an optical path difference that is equal to or similar to the hollow cavity optical path distance” (see rejection under 35 U.S.C. 112(b) above; Andrews fig. 5 and col 9 ll. 63 – col 10 ll. 13 discloses an interferometer 58 receiving signals from a Fabry-Perot type fiber 40 shown in fig. 4 with a gap of length S; two legs of the interferometer (Leg A and Leg B) have differing path lengths – leg A has a path length of 1 and leg B has a path length of 1 + 2S, making the difference between the legs 2S; the difference is a scalar multiple of the hollow cavity optical path difference, consistent with the interpretation under 35 U.S.C. 112(b) above and reads on the claim – examiner suggests replacing “equal to or similar to” with some other language supported by the specification, in light of MPEP §2173.05(b) III. Approximations). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen when modified by Islam and Mahmoud to incorporate wherein the second optical path length differs from the first optical path length by an optical path difference that is equal to or similar to the hollow cavity optical path distance as suggested by Andrews for the advantage of outputting an output signal that is linear with respect to the detected temperature, pressure, strain, etc. while having a wide dynamic range and having reduced sensitivity to temperature and vibration (Andrews col 2 ll. 44-54 and col. 11 ll. 9-32). Regarding claim 5, Kempen when modified by Islam, Mahmoud, and Andrews discloses the method of claim 4, and Kempen further teaches the method of claim 4, wherein: the first optical path include a first optical fiber, extending a first optical fiber length to a first optical fiber distal end (Kempen fig. 1 and col 3 ll. 58 – col 4 ll. 12 discloses the use of optical fibers to deliver light to the interferometer 14; Islam has been cited explicitly to teach routing sensor reflections to an interferometer from at least one Fabry-Perot fiber [analogous to the test mirror assembly 35 of Kempen]; while Islam does not explicitly disclose the use of an optical fiber along the first optical path, given the broad use of optical fibers the local and opposite ends [i.e. distal end] to connect the interferometer with a photodetector of Kempen, the first optical path of Islam therefore would obviously include a first optical fiber, extending a first optical fiber length to a first optical fiber distal end [i.e. the distal end of the first optical fiber would be placed at the corresponding reflector]), the second optical path includes a second optical fiber, separate from the first optical fiber, and extending a second optical fiber path length to a second optical fiber distal end (as with the reasoning above, the second optical path of Islam would include a second optical fiber which would be separate from the first optical fiber [separated by beamsplitter BS of Islam (analogous to optical coupler 24 of Kempen)], that extends a second optical fiber path length to a second optical fiber distal end [the second optical fiber distal end terminates at the corresponding reflector]); the first reflector is positioned at the first optical fiber distal end (the first optical path of Islam therefore would obviously include a first optical fiber, extending a first optical fiber length to a first optical fiber distal end terminating at the first reflector [i.e. the distal end of the first optical fiber would be placed at the corresponding [first] reflector]), and the second reflector is positioned at the second optical fiber distal end (the second optical fiber extends a second optical fiber path length to the second optical fiber distal end, where the second optical fiber end terminates at the second reflector [i.e. distal end of the optical fiber would be placed at the corresponding [second] reflector]). Regarding claim 7, Kempen when modified by Islam, Mahmoud, and Andrews discloses the method of claim 4, and Kempen further teaches the method further comprising: tapping a portion of the sensor reflections, as tapped sensor reflection signals (Kempen figs 2-3 and col 10 ll. 26-31 discloses the process by which the pressure applied to mirror M2 is obtained – the signals used during the calculation of pressure are considered a “tapped portion” of the sensor reflection signals, consistent with the broadest reasonable interpretation of the claim); and performing a computerized absolute measuring of the pressure, acceleration, or strain comprising computerized absolute measuring of changes in the hollow cavity optical path distance, based on the tapped sensor reflection signals (Kempen col. 10 ll. 55-60 discloses that the pressure sensor system allows for absolute measurements of the position of the test mirror [absolute measuring of the hollow cavity optical path difference]; col. 5 ll. 16-25 discloses the computerized measurement of the pressure P applied to the transducer surface 20 [where measuring pressure is dependent on measuring the hollow cavity optical path difference]). Regarding claim 24, Kempen when modified by Islam and Mahmoud discloses the system of claim 21. Kempen is silent to the system of claim 21, wherein the interferometer is further configured to perform dual path propagating of the routed cavity body reflection signals, the dual path propagating including: propagating a first portion of the routed cavity body reflection signals to the first reflector, along a first optical propagation path having a first optical path length, propagating a second portion of the routed cavity body reflection signals to the second reflector, along a second optical propagation path having a second optical path length. However, Islam does address these limitations. Islam discloses the system of claim 21, “wherein the interferometer is further configured to perform dual path propagating of the routed cavity body reflection signals” (Islam fig. 1 shows two separate optical paths from the beam splitter, one to the mirror with PZT and the other to the mirror with motorized stage [dual path propagating]), “the dual path propagating including: propagating a first portion of the routed cavity body reflection signals to the first reflector, along a first optical propagation path having a first optical path length” (Islam fig. 1; the portion of the routed sensor reflection signals to the mirror with PZT occurs along a first optical propagation path having a first optical path length), and propagating a second portion of the routed cavity body reflection signals to the second reflector, along a second optical propagation path having a second optical path length (Islam fig. 1; the other portion of the routed sensor reflection signals being routed to the mirror with the motorized stage occurs along a second optical propagation path having a second optical path length). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen to incorporate wherein the interferometer is further configured to perform dual path propagating of the routed cavity body reflection signals, the dual path propagating including: propagating a first portion of the routed cavity body reflection signals to the first reflector, along a first optical propagation path having a first optical path length, propagating a second portion of the routed cavity body reflection signals to the second reflector, along a second optical propagation path having a second optical path length as suggested by Islam for the advantage of minimizing cross talk using a Fabry-Perot fiber-optic sensor with coherence multiplexing via the matching the difference of path length (via PZT and motorized stage) for the pressure sensor being used (Islam section 2.1.1., only page 7454). Kempen when modified by Islam and Mahmoud is silent to the system of claim 21, wherein the second optical path length differs from the first optical path length by an optical path difference equal to or similar to the hollow cavity optical path distance. However, Andrews does address this limitation. Kempen, Islam, Mahmoud, and Andrews are considered to be analogous to the present invention because they are interferometric sensors measuring either temperature, pressure, or strain. Andrews discloses the system of claim 21, “wherein the second optical path length differs from the first optical path length by an optical path difference equal to or similar to the hollow cavity optical path distance” (see rejection under 35 U.S.C. 112(b) above; Andrews fig. 5 and col 9 ll. 63 – col 10 ll. 13 discloses an interferometer 58 receiving signals from a Fabry-Perot type fiber 40 shown in fig. 4 with a gap of length S; two legs of the interferometer (Leg A and Leg B) have differing path lengths – leg A has a path length of 1 and leg B has a path length of 1 + 2S, making the difference between the legs 2S; the difference is a scalar multiple of the hollow cavity optical path difference, consistent with the interpretation under 35 U.S.C. 112(b) above and reads on the claim – examiner suggests replacing “equal to or similar to” with some other language supported by the specification, in light of MPEP §2173.05(b) III. Approximations). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen when modified by Islam and Mahmoud to incorporate wherein the second optical path length differs from the first optical path length by an optical path difference equal to or similar to the hollow cavity optical path distance as suggested by Andrews for the advantage of outputting an output signal that is linear with respect to the detected temperature, pressure, strain, etc. while having a wide dynamic range and having reduced sensitivity to temperature and vibration (Andrews col 2 ll. 44-54 and col. 11 ll. 9-32). Regarding claim 25, Kempen when modified by Islam, Mahmoud, and Andrews discloses the system of claim 24, and Kempen further teaches the system wherein: the first optical path include a first optical fiber, extending a first optical fiber length to a first optical fiber distal end (Kempen fig. 1 and col 3 ll. 58 – col 4 ll. 12 discloses the use of optical fibers to deliver light to the interferometer 14; Islam has been cited explicitly to teach routing sensor reflections to an interferometer from at least one Fabry-Perot fiber [analogous to the test mirror assembly 35 of Kempen]; while Islam does not explicitly disclose the use of an optical fiber along the first optical path, given the broad use of optical fibers the local and opposite ends [i.e. distal end] to connect the interferometer with a photodetector of Kempen, the first optical path of Islam therefore would obviously include a first optical fiber, extending a first optical fiber length to a first optical fiber distal end [i.e. the distal end of the first optical fiber would be placed at the corresponding reflector]), the second optical path includes a second optical fiber, separate from the first optical fiber, and extending a second optical fiber path length to a second optical fiber distal end (as with the reasoning above, the second optical path of Islam would include a second optical fiber which would be separate from the first optical fiber [separated by beamsplitter BS of Islam (analogous to optical coupler 24 of Kempen)], that extends a second optical fiber path length to a second optical fiber distal end [the second optical fiber distal end terminates at the corresponding reflector]), the first reflector is positioned at the first optical fiber distal end (the first optical path of Islam therefore would obviously include a first optical fiber, extending a first optical fiber length to a first optical fiber distal end terminating at the first reflector [i.e. the distal end of the first optical fiber would be placed at the corresponding [first] reflector]), and the second reflector is positioned at the second optical fiber distal end (the second optical fiber extends a second optical fiber path length to the second optical fiber distal end, where the second optical fiber end terminates at the second reflector [i.e. distal end of the optical fiber would be placed at the corresponding [second] reflector]). Claims 8-9 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Kempen in view of Islam, in view of Mahmoud, in view of Andrews, and further in view of US 2017/0122828 A1 by Ralf-Dieter Pechstedt et al. (herein after “Pechstedt”). Regarding claim 8, Kempen when modified by Islam, Mahmoud, and Andrews discloses the method of claim 4, and Kempen further teaches the method wherein: the sensor optical path includes a cavity body second reflecting surface and a cavity body third reflecting surface (Kempen fig. 1 includes reflective surfaces M1 and M2 along the optical path of the sensor illustrated by optical fiber 22c as indicated in claim 1; regardless of the nomenclature of the claim, the reflective surface M1 and M2 read on two cavity body reflecting surfaces), the cavity body second reflecting surface is the hollow cavity first facing surface and the cavity body third reflecting surface is an inner face of the cap and is the hollow cavity second facing surface (as indicated in the previous limitation, the reflective surfaces M1 and M2 of Kempen are the cavity body second reflecting surface and the cavity body third reflecting surface, where M-1 is the hollow cavity first facing surface [facing the hollow cavity denoted by x in fig. 4, and M2 is the hollow cavity second facing surface [facing the hollow cavity on the opposite side to M1), and the method further comprises: tapping a portion of the sensor reflections, as tapped sensor reflection signals (Kempen figs 2-3 and col 10 ll. 26-31 discloses the process by which the pressure applied to mirror M2 is obtained – the signals used during the calculation of pressure are considered a “tapped portion” of the sensor reflection signals, consistent with the broadest reasonable interpretation of the claim), and performing an absolute measuring of a pressure, comprising an absolute measuring of at least one optical path difference within the sensor cavity body, between the cavity body second reflecting surface and the cavity body third reflecting surface (Kempen col. 10 ll. 55-60 discloses that the pressure sensor system allows for absolute measurements of the position of the test mirror, i.e. measuring the optical path difference x between M1 and M2- [absolute measuring of the hollow cavity optical path difference between the cavity body second reflecting surface and the cavity body third reflecting surface]; col. 5 ll. 16-25 discloses the computerized measurement of the pressure P applied to the transducer surface 20 [where measuring pressure is dependent on measuring the hollow cavity optical path difference]; the remaining limitations regarding measuring the optical path difference between the cavity body first reflecting surface and cavity body second reflecting surface (and between the third and fourth) are not considered here due to the “or” statement). Kempen when modified by Islam, Mahmoud, and Andrews is silent to the method of claim 4, wherein: the sensor optical path includes cavity body first reflecting surface and a cavity body fourth reflecting surface, the cavity body first reflecting surface being an outer surface of the cylinder base on which the injected light is first incident and the cavity body fourth reflecting surface is an outward facing surface of the cap, and the method further comprises: performing an absolute measuring of a temperature. However, Pechstedt does address this limitation. Kempen, Islam, Mahmoud, Andrews, and Pechstedt are considered to be analogous to the present invention because they are interferometric sensors measuring either temperature, pressure, or strain. Pechstedt discloses the method of claim 4, “wherein: the sensor optical path includes cavity body first reflecting surface and a cavity body fourth reflecting surface” (Pechstedt [0037] and fig. 2 discloses an optical pressure sensor wherein a light source 10 delivers probe light to a sensor head 14 through optical fiber 17 [sensor optical path]; [0043] the sensor head has a Fabry-Perot cavity formed from opposing major surfaces of the cavity, where reflective surfaces of the substrate and membrane form the cavity), “the cavity body first reflecting surface being an outer surface of the cylinder base on which the injected light is first incident and the cavity body fourth reflecting surface is an outward facing surface of the cap” (Pechstedt fig 2 shows optical fiber 17 delivering light to the first/outer surface of membrane 24 [cavity body first reflecting surface], and a cavity body fourth reflecting surface of 24 at the opposite end [outwardly facing surface of the cap]), “the method further comprises: performing an absolute measuring of a temperature” (Pechstedt [0043] discloses that the cavity is temperature sensing; fig. 6 shows a measure of temperature as a function of time [for a portion of signals obtained during some time interval (i.e. tapped signals) temperature is measured). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen in view of Islam, Mahmoud, and Andrews to incorporate wherein the sensor optical path includes cavity body first reflecting surface and a cavity body fourth reflecting surface, the cavity body first reflecting surface being an outer surface of the cylinder base on which the injected light is first incident and the cavity body fourth reflecting surface is an outward facing surface of the cap, and performing an absolute measuring of a temperature as suggested by Pechstedt for the advantage of integrating an temperature compensation function to existing pressure sensors, having temperature detection at the optical pressure measurement site increasing the accuracy of temperature compensation (Pechstedt [0007]). Regarding claim 9, Kempen when modified by Islam, Mahmoud, Andrews, and Pechstedt discloses the method of claim 8. Kempen when modified by Islam, Mahmoud, and Andrews is silent to the method of claim 8, wherein the absolute measuring of at least one optical path difference within the sensor cavity body comprises a Fourier optical spectrometry process. However, Pechstedt does address this limitation. Pechstedt discloses the method of claim 8, “wherein the absolute measuring of at least one optical path difference within the sensor cavity body comprises a Fourier optical spectrometry process” (Pechstedt [0052] discloses the use of a spectrometer to obtain an interference spectrum resulting from interaction of probe light with temperature sensing cavity; the temperature sensing cavity output 72 is obtained via discrete Fourier transform of the interference spectrum; one or more peaks in the Fourier transform corresponds to optical path length of optical cavities in the sensor [absolute measuring of at least one optical path difference comprises Fourier optical spectrometry process]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen in view of Islam, Mahmoud, and Andrews to incorporate wherein the absolute measuring of at least one optical path difference within the sensor cavity body comprises a Fourier optical spectrometry process as suggested by Pechstedt for the advantage of integrating an temperature compensation function to existing pressure sensors, having temperature detection at the optical pressure measurement site increasing the accuracy of temperature compensation (Pechstedt [0007]). Regarding claim 12, Kempen when modified by Islam, Mahmoud, Andrews, and Pechstedt discloses the method of claim 8. Kempen when modified by Islam, Mahmoud, and Andrews is silent to the method of claim 8, wherein the absolute measuring of at least one optical path difference within the sensor cavity body comprises routing the tapped sensor reflection signals to an optical spectrometer and generating the absolute measure based on a Fourier spectrometry result that is output by the optical spectrometer. However, Pechstedt does address this limitation. Pechstedt discloses the method of claim 8, “wherein the absolute measuring of at least one optical path difference within the sensor cavity body comprises routing the tapped sensor reflection signals to an optical spectrometer and generating the absolute measure based on a Fourier spectrometry result that is output by the optical spectrometer” (Pechstedt [0052] discloses the use of a spectrometer to obtain an interference spectrum resulting from interaction of probe light with temperature sensing cavity; the temperature sensing cavity output 72 is obtained via discrete Fourier transform of the interference spectrum; one or more peaks in the Fourier transform corresponds to optical path length of optical cavities in the sensor [absolute measuring of at least one optical path difference comprises routing signals to an optical spectrometer and generating measure based on a Fourier spectrometry result output by spectrometer]; Kempen within claim 8 above has disclosed the tapping of sensor reflecting signals). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen in view of Islam, Mahmoud, and Andrews to incorporate wherein the absolute measuring of at least one optical path difference within the sensor cavity body comprises routing the tapped sensor reflection signals to an optical spectrometer and generating the absolute measure based on a Fourier spectrometry result that is output by the optical spectrometer as suggested by Pechstedt for the advantage of integrating an temperature compensation function to existing pressure sensors, having temperature detection at the optical pressure measurement site increasing the accuracy of temperature compensation (Pechstedt [0007]). Claims 28-29 are rejected under 35 U.S.C. 103 as being unpatentable over Kempen, in view of Islam, in view of Mahmoud, and further in view of Pachstedt. Regarding claim 28, Kempen when modified by Islam and Mahmoud discloses the system of claim 21, and Kempen further teaches the system wherein: the sensor cavity body includes a cap bonded to an open end of a cylinder base, in a configuration sealing the hollow cavity (Kempen figs 4-5 and col 7 ll. 1-32 discloses an outer ring seal 60b appearing at an otherwise open end of a pipe 50 coupled with flange 56 [cylindrical base] the pipe 50 is shown in a circular cross section in fig. 5 [i.e. cylindrical into the plane of the page]; the outer ring seal 60b seals the hollow cavity, whose length is denoted by x) and the injection light optical path includes a cavity body second reflecting surface, a cavity body third reflecting surface (Kempen fig. 1 includes reflective surfaces M1 and M2 along the optical path of the sensor cavity illustrated by optical fiber 22c [injection light optical path]; regardless of the nomenclature of the claim, the reflective surface M1 and M2 read on two cavity body reflecting surfaces), the cavity body second reflecting surface is the hollow cavity first facing surface and the cavity body third reflecting surface is an inner face of the cap and is the hollow cavity second facing surface (as indicated in the previous limitation, the reflective surfaces M1 and M2 of Kempen are the cavity body second reflecting surface and the cavity body third reflecting surface, where M-1 is the hollow cavity first facing surface [facing the hollow cavity denoted by x in fig. 4, and M2 is the hollow cavity second facing surface [facing the hollow cavity on the opposite side to M1]); and the system further comprises: a tapping logic, configured to: tap a portion of the cavity body reflection signals, as tapped cavity body reflection signals prior to the dual optical path propagating by the interferometer (Kempen figs 2-3 and col 10 ll. 26-31 discloses the process by which the pressure applied to mirror M2 is obtained – the signals used during the calculation of pressure are considered a “tapped portion” of the sensor reflection signals, consistent with the broadest reasonable interpretation of the claim; the tapped portion of the signals are obtained before routing to the interferometer of Islam disclosed in claim 21; the computer serving as the signal processing unit 18 contains the claimed tapping logic, since the computer is “configured to tap a portion of the sensor reflection signals”), and perform an absolute measuring of at least one optical path difference within the sensor cavity body, the at least one optical path difference being from among an optical path difference between the cavity body first reflecting surface and the cavity body second reflecting surface, an optical path difference between the cavity body second reflecting surface and the cavity body third reflecting surface, and an optical path difference between the cavity body third reflecting surface and the cavity body fourth reflecting surface (Kempen col. 10 ll. 55-60 discloses that the pressure sensor system allows for absolute measurements of the position of the test mirror, i.e. measuring the optical path difference x between M1 and M2- [absolute measuring of at least one optical path difference within the sensor cavity body, between the cavity body second reflecting surface and the cavity body third reflecting surface]; the remaining limitations regarding measuring the optical path difference between the cavity body first reflecting surface and cavity body second reflecting surface (and between the third and fourth) are not considered here due to the “at least one of from among” statement). Kempen when modified by Islam and Mahmoud is silent to the system of claim 21, wherein: the injection light optical path includes a cavity body first reflecting surface and a cavity body fourth reflecting surface, the cavity body first reflecting surface being an outer surface of the cylinder base on which the injected light is first incident and the cavity body fourth reflecting surface is an outward facing surface of the cap, and the method further comprises: performing an absolute measuring of a temperature. However, Pechstedt does address this limitation. Kempen, Islam, Mahmoud, and Pechstedt are considered to be analogous to the present invention because they are interferometric sensors measuring either temperature, pressure, or strain. Pechstedt discloses the system of claim 21, “wherein the injection light optical path includes a cavity body first reflecting surface and a cavity body fourth reflecting surface” (Pechstedt [0037] and fig. 2 discloses an optical pressure sensor wherein a light source 10 delivers probe light [injection light optical path] to a sensor head 14 through optical fiber 17 [sensor optical path]; [0043] the sensor head has a Fabry-Perot cavity formed from opposing major surfaces of the cavity, where reflective surfaces of the substrate and membrane form the cavity), the cavity body first reflecting surface being an outer surface of the cylinder base on which the injected light is first incident and the cavity body fourth reflecting surface is an outward facing surface of the cap” (Pechstedt fig 2 shows optical fiber 17 delivering light to the first/outer surface of membrane 24 [cavity body first reflecting surface], and a cavity body fourth reflecting surface of 24 at the opposite end [outwardly facing surface of the cap]), “and the method further comprises: performing an absolute measuring of a temperature” (Pechstedt [0043] discloses that the cavity is temperature sensing; fig. 6 shows a measure of temperature as a function of time [for a portion of signals obtained during some time interval (i.e. tapped signals) temperature is measured). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen in view of Islam and Mahmoud to incorporate wherein the injection light optical path includes [a] cavity body first reflecting surface and a cavity body fourth reflecting surface, the cavity body first reflecting surface being an outer surface of the cylinder base on which the injected light is first incident and the cavity body fourth reflecting surface is an outward facing surface of the cap, and performing an absolute measuring of a temperature as suggested by Pechstedt for the advantage of integrating an temperature compensation function to existing pressure sensors, having temperature detection at the optical pressure measurement site increasing the accuracy of temperature compensation (Pechstedt [0007]). Regarding claim 29, Kempen when modified by Islam, Mahmoud, and Pechstedt discloses the system of claim 28. Kempen when modified by Islam and Mahmoud is silent to wherein the absolute measuring of at least one optical path difference within the sensor cavity body comprises performing a Fourier optical spectrometry process. However, Pechstedt does address this limitation. Pechstedt discloses the system of claim 28, “wherein the absolute measuring of at least one optical path difference within the sensor cavity body comprises performing a Fourier optical spectrometry process” (Pechstedt [0052] discloses the use of a spectrometer to obtain an interference spectrum resulting from interaction of probe light with temperature sensing cavity; the temperature sensing cavity output 72 is obtained via discrete Fourier transform of the interference spectrum; one or more peaks in the Fourier transform corresponds to optical path length of optical cavities in the sensor [absolute measuring of at least one optical path difference comprises Fourier optical spectrometry process]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kempen in view of Islam and Mahmoud to incorporate wherein the absolute measuring of at least one optical path difference within the sensor cavity body comprises performing a Fourier optical spectrometry process as suggested by Pechstedt for the advantage of integrating an temperature compensation function to existing pressure sensors, having temperature detection at the optical pressure measurement site increasing the accuracy of temperature compensation (Pechstedt [0007]). Allowable Subject Matter Claims 6, 11, 14, 26, and 31 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter: The prior art of record neither anticipates nor renders obvious the claimed subject matter of the instant application as a whole either taken alone or in combination. In particular, a thorough search for pertinent prior art did not locate any prior art that discloses or suggests all limitations of the invention disclosed in the instant application. Regarding claim 6, the limitation “propagating the second portion of the routed sensor reflections through the first reflector and along an extending optical path to the second reflector; and reflecting the second portion of the routed sensor reflections from the second reflector, wherein the extending optical path has an optical path extension length that, summed with the segment length, corresponds to the second optical path length” is not disclosed or suggested by the prior art of record. The first and second reflectors within the interferometer of claim 1 are rendered obvious by the Michelson type interferometer within Islam, but the propagation path for the second portion of the routed sensor reflection signal going through the first reflector and along an extending optical path to the second reflector is not compatible with a Michelson type interferometer. There is nothing in the art that renders obvious or suggests a substitution of the Michelson interferometer with a different type of interferometer (i.e. a Fabry-Perot interferometer) where such a propagation path may be disclosed. For that reason, the limitation is considered allowable. Regarding claim 11, the concept of “routing the tapped sensor reflection signals to a slab interferometer and detecting, by an image sensor array, outputs from the slab interferometer” is not disclosed or suggested by the prior art of record. Similar to claim 6, the sensor reflection signals obtained from the sensor first reflecting surface and sensor second reflecting surface are routed to a Michelson type interferometer within Islam. There is nothing in the art that renders obvious or suggests a substitution of the Michelson interferometer with a different type of interferometer, in this case a slab interferometer, and routing those signals to an image sensor array. For that reason, the limitation is considered allowable. Regarding claim 11, the concept of “routing the tapped sensor reflection signals to a slab interferometer and detecting, by an image sensor array, outputs from the slab interferometer” is not disclosed or suggested by the prior art of record. Similar to claim 6, the sensor reflection signals obtained from the sensor first reflecting surface and sensor second reflecting surface are routed to a Michelson type interferometer within Islam. There is nothing in the art that renders obvious or suggests a substitution of the Michelson interferometer with a different type of interferometer, in this case a slab interferometer, and routing those signals to an image sensor array. For that reason, the limitation is considered allowable. Regarding claim 14, at least the concept of “routing the tapped sensor reflection signals to a slab interferometer which has a slab optical path difference” is not disclosed or suggested by the prior art of record. The reason for allowance is analogous to that within claim 11 above. The additional claim elements serve to define additional patentable subject matter over the prior art (determining peak positions of fringes envelopes from slab interferometer outputs, identifying matchings of slab optical path differences, etc.). For these reasons, the limitation is considered allowable. Regarding claim 26, the limitation “propagating the second portion of the routed cavity body reflection signals through the first reflector and along an extending optical path to the second reflector; and reflecting the second portion of the routed cavity body reflection signals from the second reflector, wherein the extending optical path has an optical path extension length that summed with the segment length corresponds to the second optical path length” is not disclosed or suggested by the prior art of record. The first and second reflectors within the interferometer of claim 21 are rendered obvious by the Michelson type interferometer within Islam, but the propagation path for the second portion of the routed sensor reflection signal going through the first reflector and along an extending optical path to the second reflector is not compatible with a Michelson type interferometer. There is nothing in the art that renders obvious or suggests a substitution of the Michelson interferometer with a different type of interferometer (i.e. a Fabry-Perot interferometer) where such a propagation path may be disclosed. For that reason, the limitation is considered allowable. Regarding claim 31, the concept of “routing the tapped sensor reflection signals to a slab interferometer and detecting, by an image sensor array, outputs from the slab interferometer” is not disclosed or suggested by the prior art of record. Similar to claim 26, the sensor reflection signals obtained from the sensor first reflecting surface and sensor second reflecting surface are routed to a Michelson type interferometer within Islam. There is nothing in the art that renders obvious or suggests a substitution of the Michelson interferometer with a different type of interferometer, in this case a slab interferometer, and routing those signals to an image sensor array. For that reason, the limitation is considered allowable. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOSHUA M CARLSON whose telephone number is (571)270-0065. The examiner can normally be reached Mon-Fri. 8:00AM - 5:00PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Tarifur R Chowdhury can be reached at (571) 272-2287. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /JOSHUA M CARLSON/Examiner, Art Unit 2877 /TARIFUR R CHOWDHURY/Supervisory Patent Examiner, Art Unit 2877
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Prosecution Timeline

Feb 13, 2024
Application Filed
Mar 23, 2026
Non-Final Rejection mailed — §103, §112
Jun 10, 2026
Response Filed
Aug 18, 2026
Final Rejection mailed — §103, §112 (current)

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2y 10m (~2m remaining)
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