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 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 2, 5-6, and 16-19 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.
Claim 2 recites “B1=nslow−nfast”, but does not define nslow or nfast. According to the specification, B1 is birefringence of the first PM fiber and second PM fiber, nslow and nfast are the two refractive indices whose difference defines the birefringence ([0042]). For the purposes of examination, B1 is birefringence of the first PM fiber and second PM fiber.
Claim 5 recites “B2=nslow−nfast”, but does not define nslow or nfast. According to the specification, B2 is birefringence of the third PM fiber and fourth PM fiber, nslow and nfast are the two refractive indices whose difference defines the birefringence ([0047]). For the purposes of examination, B2 is birefringence of the third PM fiber and fourth PM fiber.
Claim 6 is vague and indefinite by virtue of its dependence on claim 5.
Claim 16 recites “B1=nslow−nfast”, but does not define nslow or nfast. According to the specification, B1 is birefringence of the first PM fiber and second PM fiber, nslow and nfast are the two refractive indices whose difference defines the birefringence ([0042]). For the purposes of examination, B1 is birefringence of the first PM fiber and second PM fiber.
Claim 17 is vague and indefinite by virtue of its dependence on claim 16.
Claim 18 “B2=nslow−nfast”, but does not define nslow or nfast. According to the specification, B2 is birefringence of the third PM fiber and fourth PM fiber, nslow and nfast are the two refractive indices whose difference defines the birefringence ([0047]). For the purposes of examination, B2 is birefringence of the third PM fiber and fourth PM fiber.
Claim 19 is vague and indefinite by virtue of its dependence on claim 18.
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 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 1-10 and 14-20 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (“Silicon Photonics Multi-Function Integrated Optical Circuit for Miniaturized Fiber Optic Gyroscope”, 2023)(hereinafter, “Wang”) in view of Ohno et al. (US 2007/0030491 A1)(hereinafter, “Ohno”).
Regarding claim 1, Wang teaches a device with a grating coupler-based depolarized interferometric fiber optic gyroscope (figure 1b), comprising:
an integrated optical circuit arranged on a chip (figure 1b) and configured to receive at least one optical signal from a light source (figure 1a), wherein the integrated optical circuit comprises a first grating coupler and a second grating coupler which serve as interfaces between the integrated optical circuit and external elements (discloses the grating coupler array comprises a first and a second grating coupler, figure 1, section II design and experiments);
a fiber coil assembly having a first end and a second end (discloses fiber coil, figure 1a);
a first polarization-maintaining (PM) fiber (discloses fiber array package, figure 1b)optically coupled with the first grating coupler, wherein the first PM fiber is connected between the first grating coupler and the first end of the fiber coil (“A grating coupler array is employed for optical input/output (I/O) coupling between polarization maintaining fiber array and Si-MIOC. In contrast to LN waveguides, Si-MIOC is implemented on SOI platform that enables high refractive index contrast of 2.03 between waveguide core and cladding at 1550 nm of wavelength” ,figure 1, section II design and experiments),
a second PM fiber optically coupled with the second grating coupler(discloses the grating coupler array comprises a first and a second grating coupler, figure 1, section II design and experiments), wherein the second PM fiber is connected between the second grating coupler and the second end of the fiber coil (figure 1).
Wang fails to disclose a single-mode (SM) fiber coil; the first PM fiber connected to the first grating coupler is rotated by a first tilted angle Φ1 relative to a direction of grating stripes of the first grating coupler, where the first tilted angle Φ1 ranges from 35 degrees to 55 degrees; and the second PM fiber connected to the second grating coupler is rotated by a second tilted angle Φ2 relative to a direction of grating stripes of the second grating coupler, where the second tilted angle Φ2 ranges from 35 degrees to 55 degrees, and wherein the first PM fiber and the second PM fiber have lengths L1 and L2, respectively, where L1>Ld1, L2>Ld1, an absolute difference value between L1 and L2>Ld1, and Ld1 is a first depolarization length that depends on a peak wavelength and a spectral width of the light source.
Ohno teaches a single-mode (SM) fiber coil (20, [0021] and [0034]); the first PM fiber (18) connected to the first grating coupler (discloses a PM fiber coupled between the integrated optical circuit and the fiber coil, [0007]) is rotated by a first tilted angle Φ1 relative to a direction of grating stripes of the first grating coupler (“the first light beam is incident on one end of a fiber optic coil 20 through a third optical fiber 18”, [0007]), where the first tilted angle Φ1 ranges from 35 degrees to 55 degrees(teaches a 45° , [0007]); and the second PM fiber (20) connected to the second grating coupler is rotated by a second tilted angle Φ2 relative to a direction of grating stripes of the second grating coupler (“the second branched light beam is incident on the other end of the fiber optic coil 20 through a fourth optical fiber 21”, [0007), where the second tilted angle Φ2 ranges from 35 degrees to 55 degrees(“both polarization maintaining optical fibers 18 and 21 are connected to the optical waveguides so that their polarization axis form an angle of 45°”, [0012]), and wherein the first PM fiber (18) and the second PM fiber (20) have lengths L1 and L2 ([0011]), respectively, where L1>Ld1, L2>Ld1 ([0011]), an absolute difference value between L1 and L2>Ld1 ([0036]), and Ld1 is a first depolarization length that depends on a peak wavelength and a spectral width of the light source (discloses the required PM fiber length on wavelength, beat length, and coherence length, [0010-0011] and [0036]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate a single mode fiber coil of Ohno to Wang to improve the interferometric fiber optic gyroscope’s polarization stability.
Regarding claim 2, Wang fails to disclose wherein
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and where λ is the peak wavelength of the light source, Lc1 is coherence length, ng1 is group refractive index of the first PM fiber and the second PM fiber, Lb1 is beat length, Δλ is the spectral width of the light source, B1 is birefringence of the first PM fiber and the second PM fiber, and B1=nslow−nfast.
Ohno teaches
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where λ is the peak wavelength of the light source, Lc1 is coherence length, ng1 is group refractive index of the first PM fiber and the second PM fiber, Lb1 is beat length, Δλ is the spectral width of the light source, B1 is birefringence of the first PM fiber and the second PM fiber, and B1=nslow−nfast (discloses the use of beat length, coherence length, wavelength, and PM fiber length to determine the minimum depolarization length, “the polarization maintaining optical fibers 18 and 21 have a length L which is chosen to remove the coherence between the two orthogonal linear polarizations”, [0011]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 3, Wang fails to disclose the first depolarization length Ld1 ranges from 30 cm to 50 cm, and a ratio of the length L1 or L2 to a length of the SM fiber coil assembly ranges from 0.001% to 10%.
Ohno teaches the first depolarization length Ld1 (discloses PM fiber length should exceed a depolarization threshold, the threshold depends on coherence length, wavelength, and birefringence, [0011] and [0036]), and a ratio of the length L1 or L2 to a length of the SM fiber coil assembly([0049]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang. In this case, selecting a given the first depolarization length Ld1 ranges from 30 cm to 50 cm, and a ratio of the length L1 or L2 to a length of the SM fiber coil assembly ranges from 0.001% to 10% would have flown naturally to one of ordinary skill in the art as necessitated by the specific requirements of a given application to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 4, Wang fails to disclose further comprising: a third PM fiber connected between the first PM fiber and the first end of the SM fiber coil, wherein the third PM fiber connected to the first PM fiber is rotated by a third tilted angle Φ3 relative to a slow axis of the first PM fiber, where the third tilted angle Φ3 ranges from 35 degrees to 55 degrees; and a fourth PM fiber connected between the second PM fiber and the second end of the SM fiber coil, wherein the fourth PM fiber connected to the second PM fiber is rotated by a fourth tilted angle Φ4 relative to a slow axis of the second PM fiber, where the fourth tilted angle Φ4 ranges from 35 degrees to 55 degrees, and wherein the third PM fiber and the fourth PM fiber have lengths L3 and L4, respectively, where L3>Ld2, L4>Ld2, an absolute difference value between L3 and L4>Ld2, and Ld2 is a second depolarization length that depends on the peak wavelength and the spectral width of the light source.
Ohno teaches further comprising:
a third PM fiber connected between the first PM fiber and the first end of the SM fiber coil (discloses a third PM fiber, inserts additional PM fibers between the first/second PM fibers and the SM fiber coil, [0021]), wherein the third PM fiber connected to the first PM fiber is rotated by a third tilted angle Φ3 relative to a slow axis of the first PM fiber, where the third tilted angle Φ3 ranges from 35 degrees to 55 degrees(discloses an offset of their polarization axis by 45 degree, [0021]); and
a fourth PM fiber (55) connected between the second PM fiber and the second end of the SM fiber coil (discloses a fourth PM fiber, [0034]), wherein the fourth PM fiber connected to the second PM fiber is rotated by a fourth tilted angle Φ4 relative to a slow axis of the second PM fiber (discloses two stage PM fiber arrangement on both sides of the coil, [0034]), where the fourth tilted angle Φ4 ranges from 35 degrees to 55 degrees(“is offset by an angle of 45 degree”, [0035]), and wherein the third PM fiber and the fourth PM fiber have lengths L3 and L4 (“the fourth to the seventh optical fiber 55, 56, 57 and 58 each have a length L2, L3, L4 and L5”, [0036]), respectively, where L3>Ld2, L4>Ld2 ([0039]), an absolute difference value between L3 and L4>Ld2 (“the difference in the length of any two optical fibers is chosen to be equal to or greater than 1 L”, [0036]), and Ld2 is a second depolarization length that depends on the peak wavelength and the spectral width of the light source (discloses the required PM fiber length on wavelength, beat length, and coherence length, [0011]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 5, Wang fails to disclose
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and
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and where λ is the peak wavelength of the light source, Lc2 is coherence length, ng2 is group refractive index of the third PM fiber and the fourth PM fiber, Lb2 is beat length, Δλ is the spectral width of the light source, B2 is birefringence of the third PM fiber and the fourth PM fiber, and B2=nslow−nfast.
Ohno teaches
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and where λ is the peak wavelength of the light source, Lc2 is coherence length, ng2 is group refractive index of the third PM fiber and the fourth PM fiber, Lb2 is beat length, Δλ is the spectral width of the light source, B2 is birefringence of the third PM fiber and the fourth PM fiber, and B2=nslow−nfast (discloses the use of beat length, coherence length, wavelength, and PM fiber length to determine the minimum depolarization length, “since the fifth and the seventh optical fiber 56 and 58 have respective length L3 and L5 which are equal to or greater than L”, [0011] and [0039]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 6, Wang fails to disclose wherein a ratio of the length L1 to the length L2 is different than a ratio of the length L3 to the length L4.
Ohno teaches wherein a ratio of the length L1 to the length L2 is different than a ratio of the length L3 to the length L4 (discloses multiple PM fibers with predetermined lengths, and different absolute length differences to preserve depolarization, [0036] and [0043-0044]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 7, Wang fails to disclose wherein a ratio of the length L3 or L4 to a length of the SM fiber coil assembly ranges from 0.001% to 10%.
Ohno teaches wherein a ratio of the length L3 or L4 to a length of the SM fiber coil assembly ([0036], [0039], and [0049]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang. In this case, selecting a given a ratio of the length L3 or L4 to a length of the SM fiber coil assembly ranges from 0.001% to 10% would have flown naturally to one of ordinary skill in the art as necessitated by the specific requirements of a given application to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 8, Wang teaches further comprising: a photodiode configured to receive measured optical signals propagated from the SM fiber coil assembly at least via the first grating coupler and the second grating coupler and to convert the measured optical signals into an electrical signal for angular velocity measurement (figure 1).
Regarding claim 9, Wang teaches wherein the photodiode is an on-chip photodiode integrated into the integrated optical circuit (discloses a fiber optic gyroscope, multi-function integrated optical circuit, figure 1).
Regarding claim 10, Wang teaches further comprising a fiber array with the first PM fiber and the second PM fiber (discloses fiber array package, figure 1b), wherein the fiber array further comprises at least one fiber for optically coupling the integrated optical circuit to the light source (figure 1b).
Regarding claim 14, Wang fails to disclose wherein the first tilted angle Φ1 and the second tilted angle Φ2 are set to be different from each other or the same as each other.
Ohno teaches wherein the first tilted angle Φ1 and the second tilted angle Φ2 are set to be different from each other or the same as each other(discloses P< fiber axis alignment and angular offset, uses symmetric CW and CCW paths with the same 45° offset, [0021] and [0035]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 15, Wang teaches a device with a grating coupler-based depolarized interferometric fiber optic gyroscope (figure 1b), comprising:
a light source (figure 1a) configured to generate a light beam for providing optical signals with a peak wavelength and a spectral width (Section II. DESIGN AND EXPERIMENTS);
an integrated optical circuit arranged on a chip (figure 1b) and configured to receive the optical signals, wherein the integrated optical circuit comprises a first grating coupler and a second grating coupler (discloses the grating coupler array comprises a first and a second grating coupler, figure 1, section II design and experiments);
a fiber coil assembly having a first end and a second end opposite the first end (discloses fiber coil, figure 1a);
a first polarization-maintaining (PM) fiber (discloses fiber array package, figure 1b) optically coupled with the first grating coupler, wherein the first PM fiber is connected between the first grating coupler and the first end of the fiber coil(“A grating coupler array is employed for optical input/output (I/O) coupling between polarization maintaining fiber array and Si-MIOC. In contrast to LN waveguides, Si-MIOC is implemented on SOI platform that enables high refractive index contrast of 2.03 between waveguide core and cladding at 1550 nm of wavelength” ,figure 1, section II design and experiments),
a second PM fiber optically coupled with the second grating coupler(discloses the grating coupler array comprises a first and a second grating coupler, figure 1, section II design and experiments), wherein the second PM fiber is connected between the second grating coupler and the second end of the fiber coil(figure 1).
Wang fails to disclose a single-mode (SM) fiber coil; the first PM fiber connected to the first grating coupler is rotated by a first tilted angle Φ1 relative to a direction of grating stripes of the first grating coupler, where the first tilted angle Φ1 ranges from 35 degrees to 55 degrees; and the second PM fiber connected to the second grating coupler is rotated by a second tilted angle Φ2 relative to a direction of grating stripes of the second grating coupler, where the second tilted angle Φ2 ranges from 35 degrees to 55 degrees, and wherein the first PM fiber and the second PM fiber have lengths L1 and L2, respectively, where L1>Ld1, L2>Ld1, an absolute difference value between L1 and L2>Ld1, and Ld1 is a first depolarization length that depends on a peak wavelength and a spectral width of the light source.
Ohno teaches a single-mode (SM) fiber coil (20, [0021] and [0034]); the first PM fiber (18) connected to the first grating coupler (discloses a PM fiber coupled between the integrated optical circuit and the fiber coil, [0007]) is rotated by a first tilted angle Φ1 relative to a direction of grating stripes of the first grating coupler (“the first light beam is incident on one end of a fiber optic coil 20 through a third optical fiber 18”, [0007]), where the first tilted angle Φ1 ranges from 35 degrees to 55 degrees(teaches a 45° , [0007]); and the second PM fiber (20) connected to the second grating coupler is rotated by a second tilted angle Φ2 relative to a direction of grating stripes of the second grating coupler (“the second branched light beam is incident on the other end of the fiber optic coil 20 through a fourth optical fiber 21”, [0007), where the second tilted angle Φ2 ranges from 35 degrees to 55 degrees(“both polarization maintaining optical fibers 18 and 21 are connected to the optical waveguides so that their polarization axis form an angle of 45°”, [0012]), and wherein the first PM fiber (18) and the second PM fiber (20) have lengths L1 and L2 ([0011]), respectively, which are defined according to the peak wavelength and the spectral width (discloses the required PM fiber length on wavelength, beat length, and coherence length, [0010-0011] and [0036]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate a single mode fiber coil of Ohno to Wang to improve the interferometric fiber optic gyroscope’s polarization stability.
Regarding claim 16, Wang fails to disclose wherein L1>Ld1, L2>Ld1, an absolute difference value between L1 and L2>Ld1, and Ld1 is a first depolarization length that depends on the peak wavelength and the spectral width, and wherein Ld1=
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where λ is the peak wavelength of the light source, Lc1 is coherence length, ng1 is group refractive index of the first PM fiber and the second PM fiber, Lb1 is beat length, Δλ is the spectral width of the light source, B1 is birefringence of the first PM fiber and the second PM fiber, and B1=nslow−nfast.
Ohno teaches wherein L1>Ld1, L2>Ld1 ([0011]), an absolute difference value between L1 and L2>Ld1 ([0036]), and Ld1 is a first depolarization length that depends on the peak wavelength and the spectral width (discloses the required PM fiber length on wavelength, beat length, and coherence length, [0010-0011] and [0036]),
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where λ is the peak wavelength of the light source, Lc1 is coherence length, ng1 is group refractive index of the first PM fiber and the second PM fiber, Lb1 is beat length, Δλ is the spectral width of the light source, B1 is birefringence of the first PM fiber and the second PM fiber, and B1=nslow−nfast (discloses the use of beat length, coherence length, wavelength, and PM fiber length to determine the minimum depolarization length, “the polarization maintaining optical fibers 18 and 21 have a length L which is chosen to remove the coherence between the two orthogonal linear polarizations”, [0011]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 17, Wang fails to disclose further comprising: a third PM fiber connected between the first PM fiber and the first end of the SM fiber coil, wherein the third PM fiber connected to the first PM fiber is rotated by a third tilted angle Φ3 relative to a slow axis of the first PM fiber, where the third tilted angle Φ3 ranges from 35 degrees to 55 degrees; and a fourth PM fiber connected between the second PM fiber and the second end of the SM fiber coil, wherein the fourth PM fiber connected to the second PM fiber is rotated by a fourth tilted angle Φ4 relative to a slow axis of the second PM fiber, where the fourth tilted angle Φ4 ranges from 35 degrees to 55 degrees, and wherein the third PM fiber and the fourth PM fiber have lengths L3 and L4, respectively, where L3>Ld2, L4>Ld2, an absolute difference value between L3 and L4>Ld2, and Ld2 is a second depolarization length that depends on the peak wavelength and the spectral width of the light source.
Ohno teaches further comprising:
a third PM fiber connected between the first PM fiber and the first end of the SM fiber coil (discloses a third PM fiber, inserts additional PM fibers between the first/second PM fibers and the SM fiber coil, [0021]), wherein the third PM fiber connected to the first PM fiber is rotated by a third tilted angle Φ3 relative to a slow axis of the first PM fiber, where the third tilted angle Φ3 ranges from 35 degrees to 55 degrees(discloses an offset of their polarization axis by 45 degree, [0021]); and
a fourth PM fiber (55) connected between the second PM fiber and the second end of the SM fiber coil (discloses a fourth PM fiber, [0034]), wherein the fourth PM fiber connected to the second PM fiber is rotated by a fourth tilted angle Φ4 relative to a slow axis of the second PM fiber (discloses two stage PM fiber arrangement on both sides of the coil, [0034]), where the fourth tilted angle Φ4 ranges from 35 degrees to 55 degrees(“is offset by an angle of 45 degree”, [0035]), and wherein the third PM fiber and the fourth PM fiber have lengths L3 and L4 (“the fourth to the seventh optical fiber 55, 56, 57 and 58 each have a length L2, L3, L4 and L5”, [0036]), respectively, where L3>Ld2, L4>Ld2 ([0039]), an absolute difference value between L3 and L4>Ld2 (“the difference in the length of any two optical fibers is chosen to be equal to or greater than 1 L”, [0036]), and Ld2 is a second depolarization length that depends on the peak wavelength and the spectral width of the light source (discloses the required PM fiber length on wavelength, beat length, and coherence length, [0011]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 18, Wang fails to disclose
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and where λ is the peak wavelength of the light source, Lc2 is coherence length, ng2 is group refractive index of the third PM fiber and the fourth PM fiber, Lb2 is beat length, Δλ is the spectral width of the light source, B2 is birefringence of the third PM fiber and the fourth PM fiber, and B2=nslow−nfast.
Ohno teaches
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and where λ is the peak wavelength of the light source, Lc2 is coherence length, ng2 is group refractive index of the third PM fiber and the fourth PM fiber, Lb2 is beat length, Δλ is the spectral width of the light source, B2 is birefringence of the third PM fiber and the fourth PM fiber, and B2=nslow−nfast (discloses the use of beat length, coherence length, wavelength, and PM fiber length to determine the minimum depolarization length, “since the fifth and the seventh optical fiber 56 and 58 have respective length L3 and L5 which are equal to or greater than L”, [0011] and [0039]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 19, Wang fails to disclose wherein a ratio of the length L1 to the length L2 is different than a ratio of the length L3 to the length L4.
Ohno teaches wherein a ratio of the length L1 to the length L2 is different than a ratio of the length L3 to the length L4 (discloses multiple PM fibers with predetermined lengths, and different absolute length differences to preserve depolarization, [0036] and [0043-0044]).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to integrate PM fiber depolarization method of Ohno to Wang to improve accuracy and stability of the interferometric fiber optic gyroscope.
Regarding claim 20, Wang teaches wherein the integrated optical circuit further comprises a surface grating coupler optically coupled with the light source and receiving the optical signals for the integrated optical circuit (discloses surface grating couplers that enable high polarization extinction
Ratio, Section I. INTRODUCTION ).
Claims 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (“Silicon Photonics Multi-Function Integrated Optical Circuit for Miniaturized Fiber Optic Gyroscope”, 2023)(hereinafter, “Wang”) in view of Ohno et al. (US 2007/0030491 A1)(hereinafter, “Ohno”), further in view of Jin et al. (“a Compact Four-Axis Interferometric Fiber Optic Gyroscope Based on Multiplexing for Space Application”, 2020)(hereinafter, “Jin”).
Regarding claim 11, Wang fails to disclose wherein the integrated optical circuit has a layout for three-axis angular velocity measurement.
Jin teaches wherein the integrated optical circuit has a layout for three-axis angular velocity measurement(discloses X-axis, Y-axis, Z-axis sensing axes and three-axis IFOG, section II. MULTIPLEXING CONFIGURATIONS).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to incorporate the multi-axis sensing arrangement of Jin to Wang in view of Ohno to improve measurement redundancy, and system reliability.
Regarding claim 12, Wang fails to disclose wherein the integrated optical circuit has a layout for four-axis angular velocity measurement.
Jin teaches wherein the integrated optical circuit has a layout for four-axis angular velocity measurement (discloses X-axis, Y-axis, Z-axis, S-axis, section II. MULTIPLEXING CONFIGURATIONS).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to incorporate the multi-axis sensing arrangement of Jin to Wang in view of Ohno to improve measurement redundancy, and system reliability.
Regarding claim 13, Wang fails to disclose the integrated optical circuit has a layout for three-axis angular velocity measurement and further has a layout for additional axes as redundancy features which is integrated with the three-axis angular velocity measurement into the chip.
Jin teaches the integrated optical circuit (“the digital closed-loop single-axis IFOG consists of a light source, a coupler, a sensing axis(including a fiber coil and an integrated optic chip (IOC)), a photodetector, and a signal processing circuit”, Section I. INTRODUCTION ) has a layout for three-axis angular velocity measurement and further has a layout for additional axes as redundancy features which is integrated with the three-axis angular velocity measurement into the chip (discloses X-axis, Y-axis, Z-axis, and an additional redundant S-axis, section II. MULTIPLEXING CONFIGURATIONS).
It would have been obvious to one of ordinary skill in the art before the earliest effective filing date to incorporate the multi-axis sensing arrangement of Jin to Wang in view of Ohno to improve measurement redundancy, and system reliability.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTINA XING whose telephone number is (571)270-7743. The examiner can normally be reached Monday - Friday 9AM - 5 PM.
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, Kara Geisel can be reached at 571-272-2416. 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.
/C.X./ Examiner, Art Unit 2877
/Kara E. Geisel/ Supervisory Patent Examiner, Art Unit 2877
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