DETAILED ACTION
This office action is in response to applicant’s remarks filed on September 4, 2025. Claims 1, 3, 5, and 7 are under consideration.
Response to Arguments
Applicant's arguments filed on September 4, 2025 have been fully considered but they are not persuasive.
Applicant argues the rejection over Sengupta in view of Kalman and in further in view of Keeler is improper in that the rejection rationale is hindsight reasoning. In particular, Keeler does not explicitly teach—a lateral alignment of the multicore fiber is achieved using the central core and the angular alignment is achieved using the one or more of the surrounding cores—as recited in claim 1.
Keeler teaches aligning the two multicore fibers using microlens 620 formed on lens assembly 600 shown in Fig. 6C. Keeler teaches each lens in the subarray can be arranged to optically couple with a core and each subarray is arranged to optically couple with a single fiber, in which a plurality of fibers is arranged as a cable (Col. 5, lines 14-20). The embodiment in Figs. 6A-6D provides an embodiment of a microlens assembly wherein each core is spatially isolated from its neighbors, the micro lenses working with small gaps in the collimated space, and providing rotational alignment as provided by connectors and the associated coupler or coupling structures. Since the individual cores are meticulously aligned with the individual microlenses to the micrometer (Col. 5, line 43 - Col. 6, line 31) in combination with the teaching of rotational alignment, it would have been obvious to one having ordinary skill in the art at the effective filing date of the invention to understand the alignment process is with respect to the coupling of the respective surrounding cores. Furthermore, the coupler 960 in Figs. 9A show adjusters 963 vary the collimating gaps between the two multicore fibers 920, 920’. This translational movement is in the z direction, or along the optical axis. It would have been obvious to one having ordinary skill in the art at the effective filing date of the invention to recognize the optical axis is firstly aligned (e.g., the center cores are aligned) prior to the translational movement in the z direction for adjusting the collimating gap. Therefore, the examiner considers the exact description matching the claim language (e.g., lateral alignment of the multicore fiber is achieved using the central core and the angular alignment is achieved using the one or more of the surround cores) is not necessary for one having ordinary skill in the art to understand the basic procedural orders of aligning two multicore optical fibers. For the reasons above, the examiner considers the rejection over Sengupta in view of Kalman and in further in view of Keeler teach the broadly recited limitations of claim 1 and the rejection is proper.
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 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Sengupta (US 2015/0050019 A1, herein “Sengupta”) in view of the Kalman et al. (US 2021/0320726 A1, herein “Kalman”) and in further view of Keeler et al (US 10,234,632 B1, hereinafter “Keeler”).
Regarding claim 1, Sengupta discloses a low latency free-space optical data communication channel comprising:
at least two opposing parabolic mirrors (430-1 and 430-2 of Fig. 20 or 130D-1, 130D-2 of Fig. 6) for transmitting an optical communication signal in the form of a parallel beam across a free-space channel wherein the input and output of the collimators are multicore optical fibers (450-1 and 450-2 of fig. 20), multiple cores of said multicore optical fibers are positioned at the focal points of the at least two opposing parabolic mirrors, and the at least two opposing parabolic mirrors image the optical communications signal in each core of the multiple cores of the multicore fibers into corresponding cores of opposing multicore fibers forming at least one optical communication channel. The examiner notes Fig. 20 shows the multicore optical fibers and the transmitting elements are holographic Bragging grating reflector. However, Sengupta teaches the concave mirror and holographic Bragg grating reflectors are interchangeable (Para [0010]).
Sengupta does not teach using parabolic mirrors to separate light into different channels of a multi-core fiber.
Kalman teaches using multiple parabolic reflectors (Figure 7b and Figure 9b) to separate light into different channels of a multicore fiber medium (waveguide cores 721 surrounded by waveguide cladding 723, Figure 7b; Para [0098]). It would have been obvious to one ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Kalman using parabolic reflectors in order to separate light into different channels of a multi-core fiber. This allows the light channel to be isolated within an integrated systems hence increasing the density of channels for transmission within the device.
Sengupta in view of Kalman does not teach the multicore optical fiber is a seven-core multicore fiber with one central core and six surrounding cores, and further wherein a lateral alignment of the multicore fiber is achieved using the central core and the angular alignment is achieved using the one or more of the surrounding cores.
Keeler teaches aligning first multicore fiber (MCF) to second MCF in Fig. 1. The first MCF and second MCF have 7 cores – 1 central core and 6 surrounding cores. Regarding the limitation "angular alignment" as described in applicant’s Specification paragraph [0023] which indicates the cores of the two opposing fibers are rotated to produce angular alignment of the cores. The rotation of the cores allows the cores to be "angularly aligned" which allows the opposing outer fibers to be in alignment and coupled to each other. Keeler teaches a similar device wherein various cores are aligned to each other. In order for the light of the opposing fibers to couple, some degree of angular alignment must take place otherwise the device will not couple lights as desired and shown. Since the applicant has not specified the degree of "angular alignment" the examiner considers the prior as shown in Figure 1 of Keeler to meet the newly claimed limitations (Keeler: Col. 13, lines31-47).
It would have been obvious to one having ordinary skill in art to recognize efficient coupling of 7-cores multicore fibers as taught by Keeler would be adopted in the invention of Sengupta in view of Kalman, which have multicore fibers for input and output. One would be motivated employ the alignment steps of Keeler to increase coupling efficiency and reduce coupling loss in multicore fibers.
Regarding claim 7, Sengupta discloses the same multicore fiber in a free space optical data communication channel as recited in claim 1. Therefore, the examiner considers the multicore fiber of Sengupta would be capable of receiving visible light to 1650 nm at any frequency from lasers or LEDS in copropagating or counter propagation directions enable data rates of 100’s of Tbps without chromatic dispersion or absorption typically occurring in optical fiber.
Claims 3-5 are rejected under 35 U.S.C. 103 as being unpatentable over Sengupta / Kalman in view of Keeler, and further in view of Le Taillandier De Gabory et al. (US 2019/0140418 A1, hereinafter “Gabory”).
Regarding claim 3, Sengupta/Kalman in view of Keeler disclose the invention of claim 1, but do not teach the power monitoring for surrounding cores are done by tapping into a power of that channel using an optical splitter with less than 30% tapped power and allowing greater than 70% channel power.
Gabory teaches the multicore fiber in the optical amplifier (100) has a power tapping element (180) for power monitoring of the individual cores (channels) (Fig. 2). Gabory further teaches the splitters in alternative embodiment has variable splitting ratio in order to improve the precision of the output power and the reduction of the difference between cores. The splitting rations can be tuned by the control circuit (232) which improves the quality of the transmitting signal (Para [0072]).
It would have been obvious to one having ordinary skill in the art to recognize the variable power monitoring element of Gabory would be modifiable to the multicore fiber of Sengupta/Kalman in view of Keeler for monitoring the power of individual cores or channels. One would be motivated to employ the variable power monitoring element of Gabory to ensure sufficient power is remaining in the channel for a strong transmitting signal.
Regarding claims 4 and 5, Sengupta/Kalman in view Keeler and in further of Gabory do not teach at least a three-core multicore fiber with one central core and at least two surrounding cores is used, and a lateral and angular alignment of multicore fiber is achieved using one or more of the surrounding cores. However, the examiner considers the limitation of using at least one central core and at least two surround cores is intended use. The multicore as disclosed by Sengupta/Kalman in view of Keeler and in further view Gabory is structurally the same as the multicore core fiber as broadly recited and the multicore of Sengupta/Kalman in view of Keeler and in further view Gabory is capable of functioning as recited. Therefore, the examiner considers the intended use limitations of claim 4 is satisfied. See MPEP § 2111.02 (II).
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Erin D Chiem whose telephone number is (571)272-3102. The examiner can normally be reached 10 am - 6 pm.
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/ERIN D CHIEM/Examiner, Art Unit 2874
/THOMAS A HOLLWEG/Supervisory Patent Examiner, Art Unit 2874