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 .
Claim Objections
Claim 1 is objected to because of the following informalities:
Lines 2-10 will be read as:
“a laser that outputs first continuous light having a single frequency;
an amplified spontaneous emission (ASE) light source that generates second continuous light that has a frequency component broader than a frequency of the first continuous light output by the laser and enters the second continuous light into one end of an optical fiber to be measured;
a pulse generator that pulses the first continuous light from the laser and enters the pulsed light into another end of the optical fiber;
a modulator that generates local light obtained by shifting the frequency of the first continuous light from the laser by any frequency; and”
Appropriate correction is required.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitation(s) is/are: "a signal processing unit" in claim 2.
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
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:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
Considering objective evidence present in the application indicating obviousness or non-obviousness.
Claim(s) 1-4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nikles et al. (US 2016/0025524 A1) in view of Issa et al. (US 2022/0113169 A1) and Matsuura et al. (US 2023/0324202 A1).
Regarding independent Claim 1, Nikles discloses a Brillouin gain analysis device comprising:
a laser (Figure 6: element 51 is a first laser source; [0228]) that outputs first continuous light having a single frequency ([0068] “The laser source may generate a continuous wave”);
a light source (Figure 6: element 50 is a second laser source; [0028]) that generates second continuous light ([0068] “The laser source may generate a continuous wave”) and enters the second continuous light into one end of an optical fiber to be measured (Figure 6; [0141] “route the optical probe signal through the optical multiplexer 7 toward a second fiber 22 … connected to the distal end of the sensing fiber 21”); and
a pulse generator (Figure 6: element 9 is a pulse generator; [0127]) that pulses the first continuous light ([0068] “a continuous wave”) from the laser (Figure 6: element 51 is a first laser source; [0228]) and enters the pulsed light ([0127] “an optical pulsed signal”) into another end of the optical fiber (Figure 6; [0129] “The optical pulsed signal is then routed through an optical circulator 10 and an optical multiplexer 7 toward a sensing fiber 21”), but does not specifically teach:
an amplified spontaneous emission (ASE) light source that generates second continuous light that has a frequency component broader than a frequency of the first continuous light output by the laser and enters the second continuous light into one end of an optical fiber to be measured;
a modulator that generates local light obtained by shifting the frequency of the first continuous light from the laser by any frequency; and
a detector that heterodyne-detects Brillouin scattered light generated by the optical fiber and the local light.
However, Issa, in the same field of distributed optical sensing, teaches an amplified spontaneous emission (ASE) light source (Figure 13; [0189] “the broadband amplified spontaneous emission (ASE) from the amplifier 1301 functions as the optical source”) that generates second continuous light ([0118] “an optical amplifier which produces a continuous output of amplified spontaneous emission (ASE)”) and enters the second continuous light into one end of an optical fiber to be measured (Figure 13; [0189] “directed towards the sensing fibre”; element 160 is a sensing medium such as a sensing fiber; [0150]).
Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the device of Nikles with the teachings of Issa, for an amplified spontaneous emission (ASE) light source that generates second continuous light that has a frequency component broader than a frequency of the first continuous light output by the laser and enters the second continuous light into one end of an optical fiber to be measured, because using a broadband amplified spontaneous emission light source as a probe in Brillouin gain analysis allows for simultaneous, sweep-free interrogation of the entire Brillouin gain spectrum, which eliminates the need for slow frequency tuning, reduces polarization fading, and simplifies system architecture for real-time sensing.
Nikles is also silent with respect to: a modulator that generates local light obtained by shifting the frequency of the first continuous light from the laser by any frequency; and
a detector that heterodyne-detects Brillouin scattered light generated by the optical fiber and the local light.
However, Matsuura, in the same field of optical fiber characteristic measurement, teaches a modulator (Figure 1: element 11b is a modulator; [0019]) that generates local light (Figure 1; [0023] “a first optical splitter (12) configured to split frequency-modulated light (L1) into pump light (L11) and reference light (L12)”, wherein “reference light (L12)” is local light) obtained by shifting the frequency of the first continuous light from the laser by any frequency (Figure 1; [0019] “a modulator (11 b) configured to process the driving signal … to modulate the light emitted from the light source to set the spectral width to the second width”); and
a detector (Figure 1: element 16 is a light detector; [0016]) that heterodyne-detects Brillouin scattered light generated by the optical fiber and the local light (Figure 1; [0066] “light detector 16 performs optical heterodyne detection by causing the Brillouin scattered light LS and the reference light L12 included in the two beams of light output from the optical combiner 15 to interfere with each other”).
Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the device of Nikles with the teachings of Matsuura, for a modulator that generates local light obtained by shifting the frequency of the first continuous light from the laser by any frequency; and a detector that heterodyne-detects Brillouin scattered light generated by the optical fiber and the local light, because “an object thereof is to provide an optical fiber characteristic measurement device, an optical fiber characteristic measurement program, and an optical fiber characteristic measurement method that make it possible to measure a large strain applied to an optical fiber under test and temperature change without any error.” (Matsuura, para 15)
Regarding Claim 2, modified Nikles discloses the Brillouin gain analysis device according to claim 1, but does not specifically teach:
a signal processing unit that performs Fourier transform on a signal heterodyne-detected by the detector to detect a Brillouin gain spectrum (BGS) and acquire a vibration distribution of the optical fiber from a time-series change in a peak of the BGS.
However, Matsuura, in the same field of optical fiber characteristic measurement, teaches a signal processing unit (Figure 1: element 17 is a frequency analyzer [0030]; element 18b is a signal processor [0016]) that performs Fourier transform (Figure 1; [0067] “frequency analyzer 17 may include a time axis measurer such as an oscilloscope … and a converter that performs fast Fourier transform”) on a signal heterodyne-detected by the detector (Figure 1; [0067] “frequency analyzer 17 performs frequency analysis on the detection signal S1 which is output from the light detector 16”; [0066] “light detector 16 performs optical heterodyne detection”) to detect a Brillouin gain spectrum (BGS) (Figure 1; [0067] “frequency analyzer 17 obtains a Brillouin gain spectrum”) and acquire a vibration distribution of the optical fiber (Figure 1; [0068] “control processor 18 comprehensively controls the operation of the optical fiber characteristic measurement device 1, and uses the frequency analysis result of the frequency analyzer 17 to perform processing required for measuring the characteristics (such as, for example, strain distribution, temperature distribution, or vibration distribution) of the optical fiber under test FUT”) from a time-series change in a peak of the BGS ([0005] “strain distribution, temperature distribution, vibration distribution, and the like in the length direction of the optical fiber under test can be measured by obtaining the amount of Brillouin frequency shift at a position where each correlation peak appears while the correlation peak is moved”).
Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the device of Nikles with the teachings of Matsuura, for a signal processing unit that performs Fourier transform on a signal heterodyne-detected by the detector to detect a Brillouin gain spectrum (BGS) and acquire a vibration distribution of the optical fiber from a time-series change in a peak of the BGS, because performing a Fourier transform on a heterodyne-detected time-domain signal moves data from a time-delay axis to a frequency-shift axis, filters out high-frequency noise and isolates the Brillouin resonance peak, retains the phase information captured by heterodyne detection, and produces the standard power or gain spectrum view used to measure material properties.
Regarding independent Claim 3, Nikles discloses a Brillouin gain analysis method comprising:
entering, as probe light (Figure 6; [0228] “a second laser source 50 for generating the optical probe signal”), continuous light ([0068] “The laser source may generate a continuous wave”) into one end of an optical fiber to be measured (Figure 6; [0141] “route the optical probe signal through the optical multiplexer 7 toward a second fiber 22 … connected to the distal end of the sensing fiber 21”);
pulsing the laser light (Figure 6: element 9 is a pulse generator; [0127] “an optical pulsed signal”) and entering the pulsed light into another end of the optical fiber (Figure 6; [0129] “The optical pulsed signal is then routed through an optical circulator 10 and an optical multiplexer 7 toward a sensing fiber 21”) as pump light ([0127] “an optical pulsed signal” is interpreted as pump light), but does not specifically teach:
entering, as probe light, amplified spontaneous emission (ASE) continuous light having a frequency component broader than a frequency of laser light having a single frequency into one end of an optical fiber to be measured;
generating local light by shifting the frequency of the laser light by any frequency; and
heterodyne-detecting Brillouin scattered light generated in the optical fiber and the local light.
However, Issa, in the same field of distributed optical sensing, teaches entering amplified spontaneous emission (ASE) continuous light (Figure 13; [0189] “the broadband amplified spontaneous emission (ASE) from the amplifier 1301 functions as the optical source”; [0118] “an optical amplifier which produces a continuous output of amplified spontaneous emission (ASE)”) into one end of an optical fiber to be measured (Figure 13; [0189] “directed towards the sensing fibre”; element 160 is a sensing medium such as a sensing fiber; [0150]).
Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the method of Nikles with the teachings of Issa, for entering, as probe light, amplified spontaneous emission (ASE) continuous light having a frequency component broader than a frequency of laser light having a single frequency into one end of an optical fiber to be measured, because using a broadband amplified spontaneous emission light source as a probe in Brillouin gain analysis allows for simultaneous, sweep-free interrogation of the entire Brillouin gain spectrum, which eliminates the need for slow frequency tuning, reduces polarization fading, and simplifies system architecture for real-time sensing.
Nikles is also silent with respect to: generating local light by shifting the frequency of the laser light by any frequency; and
heterodyne-detecting Brillouin scattered light generated in the optical fiber and the local light.
However, Matsuura, in the same field of optical fiber characteristic measurement, teaches generating local light (Figure 1; [0023] “a first optical splitter (12) configured to split frequency-modulated light (L1) into pump light (L11) and reference light (L12)”, wherein “reference light (L12)” is local light) by shifting the frequency of the laser light by any frequency (Figure 1; [0019] “a modulator (11 b) configured to process the driving signal … to modulate the light emitted from the light source to set the spectral width to the second width”); and
heterodyne-detecting Brillouin scattered light generated in the optical fiber and the local light (Figure 1; [0066] “light detector 16 performs optical heterodyne detection by causing the Brillouin scattered light LS and the reference light L12 included in the two beams of light output from the optical combiner 15 to interfere with each other”).
Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the method of Nikles with the teachings of Matsuura, for generating local light by shifting the frequency of the laser light by any frequency; and heterodyne-detecting Brillouin scattered light generated in the optical fiber and the local light, because “an object thereof is to provide an optical fiber characteristic measurement device, an optical fiber characteristic measurement program, and an optical fiber characteristic measurement method that make it possible to measure a large strain applied to an optical fiber under test and temperature change without any error.” (Matsuura, para 15)
Regarding Claim 4, modified Nikles discloses the Brillouin gain analysis method according to claim 3, but does not specifically teach:
performing Fourier transform on the heterodyne-detected signal to detect a Brillouin gain spectrum (BGS); and
acquiring a vibration distribution of the optical fiber from a time-series change in a peak of the BGS.
However, Matsuura, in the same field of optical fiber characteristic measurement, teaches performing Fourier transform (Figure 1; [0067] “a converter that performs fast Fourier transform”) on the heterodyne-detected signal (Figure 1; [0067] “on the detection signal S1 which is output from the light detector 16”; [0066] “light detector 16 performs optical heterodyne detection”) to detect a Brillouin gain spectrum (BGS) (Figure 1; [0067] “obtains a Brillouin gain spectrum”); and
acquiring a vibration distribution of the optical fiber (Figure 1; [0068] “control processor 18 comprehensively controls the operation of the optical fiber characteristic measurement device 1, and uses the frequency analysis result of the frequency analyzer 17 to perform processing required for measuring the characteristics (such as, for example, strain distribution, temperature distribution, or vibration distribution) of the optical fiber under test FUT”) from a time-series change in a peak of the BGS ([0005] “strain distribution, temperature distribution, vibration distribution, and the like in the length direction of the optical fiber under test can be measured by obtaining the amount of Brillouin frequency shift at a position where each correlation peak appears while the correlation peak is moved”).
Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the method of Nikles with the teachings of Matsuura, for performing Fourier transform on the heterodyne-detected signal to detect a Brillouin gain spectrum (BGS); and acquiring a vibration distribution of the optical fiber from a time-series change in a peak of the BGS, because performing a Fourier transform on a heterodyne-detected time-domain signal moves data from a time-delay axis to a frequency-shift axis, filters out high-frequency noise and isolates the Brillouin resonance peak, retains the phase information captured by heterodyne detection, and produces the standard power or gain spectrum view used to measure material properties.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US-20170108358-A1 discloses an apparatus intended to interrogate a distributed optical fibre sensor by means of frequency-domain analysis of the output signal of an optical interferometer that is excited by a first type of wavelength-swept laser source and that comprises the fibre sensor in its measure arm, in a configuration that allows the sensor to be also excited by a second type of laser source that is characterized by a wavelength-shift with respect to the first laser source that produces light amplification (or depletion) by stimulated Brillouin scattering within the sensing fibre.
US-20160169712-A1 discloses apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fibre that can be used for point sensors as well as distributed sensors or the combination of both. In particular, this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fibre while achieving fine spatial resolution. Advantages of this technique include a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.
US-20130308682-A1 discloses a method of distributed and dynamical Brillouin sensing in optical fibers. The method includes the following stages: deriving average characteristics of an optical fiber along its length; generating a variable frequency probe signal, such that the variable frequency is tailored to match, at specified points along the fiber, the respective average characteristics; injecting the variable frequency probe signal to a first end of the optical fiber and a periodic pulse signal to a second end of the optical fiber, wherein the injecting is synchronized such that a stimulated Brillouin scattering is carried out at each one of the specified points along the optical fiber, such that a frequency difference between the probe signal and the pump signal matches the average characteristics of the fiber; and measuring occurrences of the stimulated Brillouin scattering, to yield data indicative of strain and temperature at all points along the optical fiber.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Akbar H Rizvi whose telephone number is (571) 272-5085. The examiner can normally be reached Monday - Friday, 9:30 am - 6:30 pm.
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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.
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/AKBAR H. RIZVI/
Examiner, Art Unit 2877
/TARIFUR R CHOWDHURY/Supervisory Patent Examiner, Art Unit 2877
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