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
Claims 1-5 are objected to because of the following informalities:
Regarding claim 1, “core pitch of” should perhaps read --core pitch such that--.
Regarding claim 3, “bending at” should perhaps read --bending the rare-earth doped fiber at--.
Regarding claim 4, “gain characteristics 0.1 dB” should perhaps read--gain characteristics at 0.1 dB--.
Regarding claim 5, “gain characteristics 0.5 dB” should perhaps read--gain characteristics at 0.5 dB--.
Claims 2-5 are further objected to by virtue of dependency.
Appropriate correction is requested.
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.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Jollivet (“Mode-resolved gain analysis and lasing in multi-supermode multi-core fiber laser,” published 2014)1 in view of Okamoto (“Fundamentals of optical waveguides,” published 2006)2.
Regarding claim 1, Jollivet discloses a rare-earth doped fiber including a plurality of cores (Fig. 1a), wherein
a v value of the plurality of cores is less than 2.405 (p. 30379, § 2, v parameter of 1.8), and
the plurality of cores has a core pitch (p. 30379, § 2, pitch of 9.3 µm) […].
Jollivet does not define a normalized coupling coefficient nor teach its numerical value, specifically: [the plurality of cores has a core pitch] “of a normalized coupling coefficient of 1.0 × 10-3 or more.” However, Okamoto teaches the relationship between the core pitch and normalized coupling coefficient on p. 187 and Fig. 4.16. Specifically, Fig. 4.16 identifies κa / √Δ as the normalized coupling coefficient and D / a as the relative core center separation. Therefore, in accordance with Fig. 4.16 of Okamoto, for v = 1.8 and D / a = 3.152542 (Jollivet, p. 30379, § 2, core radius a = (5.9 µm)/2 and core pitch D = 9.3 µm), the normalized coupling coefficient greater than 10-3. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to configure the core pitch of Jollivet according to the normalized coupling relationship taught by Okamoto. The modification applies a known technique to a known coupled core optical fiber ready for improvement and would have yielded predictable results (KSR rationale D). Specifically, applying the relationship of Okamoto to the fiber of Jollivet provides quantified evanescent coupling associated with supermode formation, while improving the predictability and controls of the coupling strength. The skilled artisan would have recognized the benefits of Okamoto to select and verify the core spacing, and the update would have been pursued and accomplished with predictable results.
Claims 2-3 are rejected under 35 U.S.C. 103 as being unpatentable over Jollivet in view of Okamoto further in view of Valles (“Optimized active multicore fiber bending sensor,” published 2019)3.
Regarding claim 2, Jollivet in view of Okamoto teaches the rare-earth doped fiber according to claim 1, and further teaches: an optical amplifier comprising the rare-earth doped fiber (Jollivet, Fig. 4 as detailed in Fig. 6), wherein the optical amplifier amplifies propagating light in the rare-earth doped fiber (Jollivet, pp. 30381-2, § 3, 1.06 µm seed laser light amplification), with mode-dependent gain characteristics (Jollivet, Fig. 6c, p. 30383, § 3, different γi values for different supermodes) [1: …], on injection of excitation light into a clad part of the rare-earth doped fiber (Jollivet, Fig. 4, p. 30381-2, § 3, 976 nm pump placed in the first cladding) in a state of being bent (Jollivet, Figs. 6a & 6c, p. 30383, § 3, perturbing the amplifier fiber of Fig. 4 in a coiled condition) [2: …].
Jollivet in view of Okamoto does not teach (1) “dependent on a predetermined bending radius”; and, (2) “at the bending radius” as Jollivet does not identify the radius of its coil. However, Valles teaches amplification dependent on a predetermined bending radius in Fig. 2 and p. 54, §§ 2.2-2.3, and further teaching bending the active fiber at the selected radius in Fig. 7b and pp. 56-57, § 3.2. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the fiber of Jollivet in view of Okamoto with the teachings of Valles with a reasonable expectation of success in order to select a fiber bending radius for the control of differential supermode loss and resulting modal amplification, thereby yielding a system with a more predictable, uniform and reliable modal output (Valles, §§ 2.2, 2.3, 3.2; Figs. 6-7).
Regarding claim 3, Jollivet in view of Okamoto further in view of Valles teaches the optical amplifier according to claim 2, and therefore teaches the method of controlling the optical amplifier according to claim 2 based on the same analysis presented in the § 103 rejection of the corresponding apparatus in claim 2, above. Jollivet in view of Okamoto further in view of Valles further teaches the method comprising reducing the mode-dependent gain characteristics by bending (Jollivet, Fig. 6, p. 30383, § 3, comparing straight and coiled conditions reporting modal amplification factor decreases from 11.8 dB to 7.6 dB when coiled; Valles, Fig. 2 and p. 54, § 2.2, increase in bending loss as radius decreases) at the predetermined bending radius (Valles, Fig. 7b and pp. 56-57, § 3.2, selected radius dependent response curve).
Allowable Subject Matter
Claims 4-5 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. A statement of reasons for the indication of allowable subject matter are as follows.
Regarding claim 4, neither Jollivet, Okamoto, nor Valles teaches the method of claim 3, “wherein the rare-earth doped fiber is a two-core erbium doped fiber having a core pitch Λ, the method comprising controlling a bending radius R based on the following expression to keep the mode-dependent gain characteristics 0.1 dB or less: R = aΛ + b a = -32.737v2 + 145.97v - 154.36
b = 474.19v2 - 2067.2v + 2169.4 where v is the v value of the plurality of cores.”
Regarding claim 5, neither Jollivet, Okamoto, nor Valles teaches the method of claim 3, “wherein the rare-earth doped fiber is a two-core erbium doped fiber having a core pitch Λ, the method comprising controlling a bending radius R based on the following expression to keep the mode-dependent gain characteristics 0.5 dB or less: R = aΛ + b a = 165.9v2 + 673.92v - 693.54 b = -1915.4v2 - 7935.6v + 8233.2where v is the v value of the plurality of cores.”
The remaining prior art made of record and not relied upon is considered pertinent to applicant’s disclosure, as noted in the attached PTO 892, include:
Sakamoto (“Characteristics of Randomly Coupled 12-core Erbium-Doped Fiber Amplifier,” published 2021)4 discloses a coupled twelve core erbium doped fiber amplifier and examines bending effects on mode dependent loss. However, Sakamoto does not teach the two core construction or the equation linking of the bending radius, core pitch, and v value to 0.1 dB and 0.5 dB mode dependent gain limits as covered in claims 4 and 5.
Ohtsuka (US 20210242655 A1) discloses an erbium doped multicore fiber amplifier in which bending reduces crosstalk and preserve gain. However, Ohtsuka does not teach the particular two core fiber or the equations relating bending radius, core pitch, and v value to the mode dependent gain limits as covered by claims 4 and 5.
Hasegawa (US 20190115715 A1) discloses a rare earth doped multicore optical amplifier using core coupling to improv gain uniformity, however does not teach the two core erbium doped fiber no the specific bending radius equations base don core pitch and v value as covered by claims 4 and 5.
In sum, the cited prior art lacks any teaching or motivation that would lead a person of ordinary skill in the art to implement the features of claims 4-5, thereby failing to render the claimed invention anticipated or obvious. Accordingly, claims 4-5 would be allowable if rewritten in independent form, including all limitations of its base claim and any intervening claims.
Conclusion
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/ZHENGQING QI/Examiner, Art Unit 3645
1 C. Jollivet et al., “Mode-resolved gain analysis and lasing in multi-supermode multi-core fiber laser,” Opt. Express 22, 30377-30386 (2014).
2 K. Okamoto, Fundamentals of Optical Waveguides, 2nd ed. Academic Press, 2006, Ch. 4, pp. 159-207.
3 Vallés, J. A., & Benedicto, D. (2019). Optimized active multicore fiber bending sensor. Optical Materials, 87, 53-57.
4 T. Sakamoto, M. Wada, S. Aozasa, R. Imada, T. Yamamoto and K. Nakajima, “Characteristics of Randomly Coupled 12-core Erbium-Doped Fiber Amplifier,” in Journal of Lightwave Technology, vol. 39, no. 4, pp. 1186-1193, 15 Feb.15, 2021.
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