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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 01/08/25; 12/17/24 & 08/10/24 has been acknowledged. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-3, 7-8, 10, 12-14, and 16-17 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Issa et al (US 2020/0209020 hereinafter “Issa”).
Regarding claims 1 and 10; Issa discloses an apparatus and method (figures 1, 3, 123, 15, and 17) comprising:
an optical transmitter (101 @ figures 1 and 3) configured to inject first and second OFDR probe signals (151, 153 @ figure 1 and paragraph [0160]) into an optical fiber cable (160 @ figures 1 and 3) on respective, mutually orthogonal first and second probe channels (figure 9 and paragraph [0188]: e.g., The light which is directed towards to the phase and amplitude receiver and its associated polarization states are labelled 905. In this arrangement, the two orthogonal polarizations in a single fibre act as independent optical paths);
a coherent optical receiver (131 @ figures 1 and 3) configured to measure portions of the first and second probe signals (151, 153 @ figure 1) received in response to backscattering of the probe signals (161a, 161b or 163a, 163b @ figure 1) at a scatterer in the optical fiber cable (160 @ figure 1); and
a digital processing circuit (135 @ figure 1) configured to estimate, from the measured portions of the first and second probe signals (151, 153 @ figure 1), a time value indicative of a round-trip propagation time (paragraphs [0070] and [0160]: e.g., the difference delay imparted on the separated signals 151 and 153 in the IRDP 106a is preferably (although not necessarily) longer than the round-trip time of light in the sensing medium 160) for light of said first and second probe signals in the optical fiber (160 @ figures 1 and 3). See figures 1-19
Regarding claims 2 and 13; Issa discloses the digital processing circuit (135 @ figure 1) is configured to estimate the indicative time value by evaluating a difference of time-dependent phases of the measured portions of the first and second probe signals (paragraphs [0065] and [0075]: e.g., the system may further comprise a phase and amplitude receiver adapted to detect an interference signal between the first delayed backscattered optical signal and the second delayed backscattered optical signal to determine a phase variance between the first delayed backscattered optical signal and the second delayed backscattered optical signal indicative of an external disturbance causing an optical path difference in the optically transparent medium).
Regarding claims 3 and 14; Issa discloses the optical transmitter (102 @ figures 1 and 3) is configured to inject the first and second OFDR probe signals (151, 153 @ figure 1) while linearly sweeping frequencies (figures 10-11 and paragraph [0172]: e.g., frequency shifting (e.g. acousto-optic frequency shifting) the Direct+Delay and/or Delay+Direct signals and complex demodulation to recover phase; 3×3 coupler or M×N coupler where M≥2 or N≥3; frequency sweeping and Hilbert transform for recovery of phase; phase modulator receiving phase through time multiplexing of a changing phase shift) of said first and second OFDR probe signals (151, 153 @ figure 1).
Regarding claims 7-8 and 16-17; Issa discloses the optical transmitter (102 @ figures 1 and 3) is configured to inject the first and second OFDR probe signals (151, 153 @ figures 1 and 3) into the optical fiber cable (160 @ figures 1 and 3) on respective, mutually orthogonal polarization channels (figure 9 and paragraph [0188]: e.g., The light which is directed towards to the phase and amplitude receiver and its associated polarization states are labelled 905. In this arrangement, the two orthogonal polarizations in a single fibre act as independent optical paths).
Regarding claim 12; Issa discloses the estimating is performed using a digital processing circuit (135 @ figures 1 and 3)
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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 4 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Issa et al (US 2020/0209020 hereinafter “Issa”) in view of Ip et al (US 2021/0356316 hereinafter “Ip”).
Regarding claims 4 and 15; Issa discloses all of feature of claimed invention except for the optical transmitter is configured to sweep the respective frequencies of the first and second OFDR probe signals in opposite directions. However, Ip teaches that it is known in the art to provide the optical transmitter (figure 2) is configured to sweep the respective frequencies of the first and second OFDR probe signals (probe pulses have the opposite direction in figure 4 and abstract) in opposite directions (figure 4). It would have been obvious to one having ordinary skill in the art before the effective filling date of claimed invention to combine apparatus and method of Issa with limitation above as taught by IP for the purpose of improving signal-to-noise of distributed acoustic sensing (DAS) systems using coherent detection of Rayleigh backscatter in multi-span links.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Issa et al (US 2020/0209020 hereinafter “Issa”) in view of Ip et al (US 2021/0364345 hereinafter “Ip (‘345)”).
Regarding claim 11; Issa discloses all of feature of claimed invention except for the backscattered content is received in a coherent optical receiver. However, Ip (‘345) teaches that it is known in the art to provide the backscattered content is received in a coherent optical receiver (figure 1 and paragraph [0026]: e.g., a correlation-based DAS interrogator including a generator that launches chirped pulses into a fiber under test (FUT), and detects by a coherent receiver Rayleigh backscatter). It would have been obvious to one having ordinary skill in the art before the effective filling date of claimed invention to combine apparatus and method of Issa with limitation above as taught by IP (‘345) for the purpose of improving detection environmental conditions such as temperature (distributed temperature sensing—DTS), vibration (distributed vibration sensing—DVS), stretch level etc. anywhere along an optical fiber cable.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Issa et al (US 2020/0209020 hereinafter “Issa”) in view of Hartog et al (US 2012/0067118 hereinafter “Hartog”).
Regarding claim 5; Issa discloses all of feature of claimed invention except for the digital processing circuit is configured to evaluate said phase difference from said measured probe-signal portions after removing phases that vary quadratically with time. However, Hartog teaches that it is known in the art to provide the digital processing circuit (152, 140 @ figures 1-2) is configured to evaluate said phase difference from said measured probe-signal portions (paragraph [0034] and abstract: e.g., A phase detection and acquisition system determines a phase difference between first and second locations along the optical fiber based on phase information extracted from the mixed output signal and combines the phase information extracted from multiple acquisitions to detect strain on the optical fiber sensor. ) after removing phases that vary quadratically with time (134 @ figures 1-2). It would have been obvious to one having ordinary skill in the art before the effective filling date of claimed invention to combine apparatus and method of Issa with limitation above as taught by Hartog for the purpose of improving the linearity of the detection system by using the phase information.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Issa et al (US 2020/0209020 hereinafter “Issa”) in view of Hartog et al (US 2012/0067118 hereinafter “Hartog”) as applied to claims5 above, and further in view of Ip et al (US 2021/0356316 hereinafter “Ip”).
Regarding claim 6; Issa in view of Hartog combination discloses all of feature of claimed invention except for the optical transmitter is configured to sweep the respective frequencies of the first and second OFDR probe signals in opposite directions. However, Ip teaches that it is known in the art to provide the optical transmitter (figure 2) is configured to sweep the respective frequencies of the first and second OFDR probe signals (probe pulses have the opposite direction in figure 4 and abstract) in opposite directions (figure 4). It would have been obvious to one having ordinary skill in the art before the effective filling date of claimed invention to combine apparatus and method of Issa with limitation above as taught by IP for the purpose of improving signal-to-noise of distributed acoustic sensing (DAS) systems using coherent detection of Rayleigh backscatter in multi-span links.
Allowable Subject Matter
Claims 9 and 18 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The prior art of record, taken alone or in combination, fails discloses or render obvious apparatus and method comprising all the specific elements with the specific combination including the optical transmitter is configured to inject the first OFDR probe signal with a first linearly swept frequency modulation envelope, and to inject the second OFDR probe signal with a second linearly swept frequency modulation envelope that is a complex conjugate of the first swept frequency modulation envelope in set forth of claims 9 and 18.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
1) Lecoeuche (US 2018/0073959) discloses a coherent receiver may acquire a backscattered signal from the DUT, and use the second laser beam as a local oscillator to determine a Brillouin trace with respect to the DUT.
2) Cedilnik (US 2020/0116556) discloses an arrangement for high rate fiber optical distributed acoustic sensing includes an optical fiber, a light launch module adapted to inject a first coherent light pattern into the optical fiber and to inject a second coherent light pattern into the optical fiber while first Rayleigh backscatter light of the first light pattern is propagating in the optical fiber.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SANG H NGUYEN whose telephone number is (571)272-2425. The examiner can normally be reached M-F.
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November 29, 2025
/SANG H NGUYEN/ Primary Examiner, Art Unit 2877