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 .
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.
Election/Restrictions
Applicant’s election without traverse of Group I, Species A in the reply filed on 16 April, 2026 is acknowledged.
Claims 3 and 5-17 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected inventions, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 16 April, 2026.
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.
Claims 1-2 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Bickham et al. (US 2021/0181408; hereinafter Bickham).
Regarding claim 1: Bickham disclosesA multi-core fiber (Figs. 1-2, multicore optical fiber 10) comprising: a plurality of core portions (Figs. 1-2, cores C.sub.i, individually denoted as C.sub.1 and C.sub.2 in the example of Figs. 1 and 2; see paragraph 0048); anda cladding portion (Figs. 1 and 2, common cladding 20) surrounding outer circumferences of the plurality of core portions and having a refractive index lower than a maximum refractive index of the plurality of core portions (see Figs. 5-10 and 12-15, in all figures, the cladding portion has a refractive index lower than the maximum refractive index of the plurality of core portions).
Additionally, Bickham teaches that the multi-core fiber has a core pitch between 10 and 20 microns (see paragraph 0064), falling within the claimed range of 20 microns or smaller, the core pitch being an interval between centers of nearest neighboring ones of the plurality of core portions in a cross section orthogonal to a longitudinal direction. Bickham further teaches that the mode field diameter of the cores is at least 5 microns at 1310 nm, and further that each core may have the same mode field diameter at each operating wavelength of 1550 nm and 1310 nm (see paragraph 0087). At least 5 microns intersects the claimed range of 5 microns or smaller, having a mode field diameter of 5 microns in common. In order to allow to accommodate the tight packing of cores without signal degradation, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to prepare the Bickham multi-core fiber having a mode field diameter of 5 microns at a wavelength of 1550 nm, following the teachings of Bickham that the mode field diameter of the cores is at least 5 microns at 1310 nm, and further that each core may have the same mode field diameter at each operating wavelength of 1550 nm and 1310 nm.
Regarding the limitations “the multi-core fiber has inter-core crosstalk of -20 dB/km or less and the multi-core fiber has a macrobending loss of 0.1 dB/m or less at the wavelength of 1550 nm when the multi-core fiber is bent at a radius of 5 mm”: When a structure recited in a reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. See MPEP 2112.01. Bickham teaches a multi-core fiber that is substantially identical to that of the claimed invention, therefore the claimed properties of “the multi-core fiber has inter-core crosstalk of -20 dB/km or less, and the multi-core fiber has a macrobending loss of 0.1 dB/m or less at the wavelength of 1550 nm when the multi-core fiber is bent at a radius of 5 mm” are presumed to be inherent. The burden is on the applicant to show that the prior art device does not inherently possess the claimed properties. See MPEP 2112.01.
The examiner notes that if the claimed structure does not inherently possess the claimed properties, then the claims would be incomplete for omitting essential structural cooperative relationships of elements, such omission amounting to a gap between the necessary structural connections necessary to clearly and precisely define the invention, wherein the structure necessary to provide the claimed properties is essential.
Regarding claim 2: Modified Bickham teachesThe multi-core fiber according to claim 1 (as applied above), comprising four or more of the plurality of core portions that are arranged in a square lattice form in the cross section orthogonal to the longitudinal direction (see paragraph 0050, square pattern; four or more core portions are understood to be needed, or at least obvious, to establish the disclosed square pattern).
Regarding claim 4: Modified Bickham teaches the multi-core fiber according to claim 1, as applied above. Bickham further teaches that the maximum refractive index of the plurality of core portions may have a relative refractive index difference Δ.sub.iMAX of “about 0.35% to about 5%”, measured with respect to pure silica, whereas the upper bound given for the cladding portion Δ.sub.CC is 0.3% (see paragraphs 0056 and 0061). When Δ.sub.iMAX is greater than 2.4%, the multi-core fiber meets the claimed condition of having cores with a relative refractive index difference with respect to the refractive index of the cladding portion of at least 2%. Based on these disclosed ranges, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to prepare the Bickham fiber having a maximum refractive index of the plurality of core portions having a relative refractive index difference of 2% or more with respect to the refractive index of the cladding portion, to achieve better light confinement in the tightly-packed cores.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Kirsten D Endresen whose telephone number is (703)756-1533. The examiner can normally be reached Monday to Thursday.
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/KIRSTEN D. ENDRESEN/Examiner, Art Unit 2874
/THOMAS A HOLLWEG/Supervisory Patent Examiner, Art Unit 2874
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