Detailed Office 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 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.
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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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 1-16
Claims 1-16 are rejected under 35 U.S.C. 103 as being unpatentable over Thomson et al. (2020/0069165; “Thomson”) in view of Mukasa, Kazunori (2011/0094269; “Mukasa”).
Regarding claim 1, Thomson discloses in figures 1 and 2, and related text and figures, embodiments of an apparatus 10 (and related methods of manufacturing) for guiding light comprising: a multi-core fiber section 12 comprising few-mode core fibers 14 and a single-core fiber section 12 comprising a multi-mode core 22, and a connecting tapered photonic lantern transition section 20. See below, Thomson – Selected Text.
Thomson – Figures 1 and 2
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Thomson – Selected Text
[0088] FIG. 1 is a schematic illustration of an imaging system 10 in accordance with an embodiment.
[0089] The imaging system 10 comprises an optical fibre 12 which is formed by tapering a multicore optical fibre. In the present embodiment, the optical fibre 12 is as described in Harikumar K. Chandrasekharan, Frauke Izdebski, Itandehui Gris-Sánchez, Nikola Krstajić, Richard Walker, Helen L. Bridle, Paul A. Dalgarno, William N. MacPherson, Robert K. Henderson, Tim A. Birks & Robert R. Thomson, Multiplexed single-mode wavelength-to-time mapping of multimode light, Nature Communications 8, 14080 (2017).
[0090] The multicore optical fibre comprises an 11×11 square array of single mode cores 14. The single mode cores 14 are single mode for wavelengths between about 470 nm and 610 nm. In other embodiments, the single mode cores 14 may be single mode for wavelengths of above around 400 nm, 500 nm, or 600 nm. The single mode cores 14 are arranged in a square grid with a spacing of 10.53 μm. Each of the single mode cores 14 is 1.63 μm in diameter. The single mode cores 14 are formed from germanium-doped silica. A cladding material for the multicore optical fibre is pure silica. The numerical aperture of the cores is 0.22 and the fibre's outer diameter is 200 μm.
[0091] In further embodiments, a spacing between the cores may be any suitable spacing that stops significant coupling of light between single mode cores after propagating down the lengths of the fibre. In some embodiments, the single mode cores are positioned more closely together by reducing the wavelength, increasing the core-cladding index contrast and/or reducing the core size.
[0092] Although in the present embodiment, the plurality of cores 14 of the multicore fibre are single mode, in other embodiments each core from the multicore fibre may support a small number of modes, for example 3 or 6 spatial modes
[0093] FIG. 2a is a schematic illustration of an end view of a proximal end 16 of the optical fibre 12, showing the plurality of single mode cores 14.
[0094] The optical fibre 12 is tapered at a distal end 18 to form a photonic lantern transition 20. In the present embodiment, the photonic lantern transition 22 is formed by placing the multicore fibre inside a low index capillary, tapering the multicore fibre, and cleaving the tapered multicore fibre near the middle of the taper. The cleaved end may be considered to form a traditional step-index core-clad multimode waveguide 22, where the core of the multimode waveguide 22 is formed out of the tapered multicore fibre, the cladding is formed out of the tapered low index capillary, and the individual cores of the multicore fibre are now too small to properly guide light.
[0095] FIG. 2b is a schematic illustration of an end view of the distal end of the optical fibre, which shows the multimode core 22. The multimode core 22 is larger than each of the single mode cores 16.
[0096] The portion of the optical fibre 12 that comprises the single mode cores 14 has a length L. The photonic lantern transition 20, including the section of multimode core 22, has a length d which is much less than L. For example, L may be a metre or more while d may be a few millimetres or tens of millimetres. Dimensions in FIG. 1 are not shown to scale.
[0097] A photonic lantern is a guided-wave device which in its ideal case couples an array of N single mode cores at one end to a multimode core supporting N guided modes at the other, where the ends are linked by an adiabatic transition. In such a transition, light injected into one core at the single mode end may be considered to slowly evolve into a coherent mode at the multimode end. The coherent mode has a specific amplitude and phase profile at the output from the lantern transition. Examples of photonic lanterns and methods of forming photonic lanterns are described in Birks, T. A., Gris-Sanchez, I., Yerolatsitis, S., Leon-Saval, S. G. & Thomson, R. R. The photonic lantern. Adv. Opt. Photon. 7, 107 (2015)
[0098] In the photonic lantern transition 20, the waveguide changes smoothly and continuously from the single mode cores 14 to the multimode core 22. Light that is input into any one of the single mode cores 14 may be distributed across most or all of the modes in the multimode core 22 to form a specific pattern of light.
[0099] It has been found that, in a photonic lantern that is formed by tapering a multicore fibre at one end, very specific multimode patterns of light may be generated at the output at the distal end of the photonic lantern when light is individually coupled into each single mode core at the proximal end of the photonic lantern, as long as the single mode cores 14 are not significantly coupled over the length of fibre used. Different light patterns may be formed by exciting different ones of the single mode cores 14. The light patterns formed by different optical fibres having the same design may be similar, but the exact light patterns formed may be unique to a given multicore fibre and guided-wave transition. For example, two photonic lanterns may be fabricated to the same design by tapering and cleaving a length of multicore fibre. However, the position where the tapered section is cleaved may not be exactly the same for both lantern transitions, causing the light patterns to differ at least slightly.
Further regarding claim 1, Mukasa discloses in figures 1-8, and related sections, embodiments of multicore fibers having large numbers of cores. See below, Mukasa – Selected Text.
Mukasa – Selected Text
[0005] A multi-core optical fiber (MCF) is a novel optical fiber including plural cores in one optical fiber, and it is capable of having many cores provided in a small space. The multi-core optical fiber is expected to achieve a large-capacity image transmission and a new optical propagation such as a spatial multiplexing transmission. Particularly, a type of a multi-core optical fiber suppressing an optical interference between cores can achieve two times the original transmission capacity when the core number doubles, and three times the original transmission capacity when the core number triples, for example. Therefore, this can become a key technique for a large-capacity transmission in the future. Accordingly, techniques of multi-core optical fibers used as optical transmission paths have been widely studied.
[0023] A manufacturing method of a multi-core optical fiber according to a first embodiment of the present invention will be explained first. FIG. 1 is a schematic cross-sectional view of a multi-core optical fiber to be manufactured by the manufacturing method according to the first embodiment. FIG. 1 is also a partially enlarged view of the cross section. As shown in FIG. 1, a multi-core optical fiber 1 includes 10,000 cores 1a and a cladding 1b formed on an external periphery of the cores 1a. The multi-core optical fiber 1 is a solid type, and a refractive index of each of the cores 1a is higher than that of the cladding 1b. Each of the cores 1a is made of silica glass with Ge being added, for example, and the cladding 1b is made of pure silica glass not containing a dopant for adjusting a refractive index, or is made of silica glass with fluoride (F) being added. The diameter of the core 1a is about 10 micrometers, and a specific refractive-index difference between the core 1a and the cladding 1b is about 0.35%. When mutual specific refractive indexes of the cores 1a are to be slightly differentiated (that is, when different kinds of cores 1a are being used) in the multi-core optical fiber 1 as described in the document by M. Koshiba et al., a distance between centers of the cores 1a is set at about 50 micrometers (at least 40 micrometers), for example. An interference of light propagating in each of the cores 1a is then suppressed, and a crosstalk can be reduced to equal to or less than -30 decibels. On the other hand, when the same kind of cores 1a having mutually the same specific refractive-indexes are used, a difference between centers of the cores 1a is at least 70 micrometers (80 micrometers, for example, considering a variation in distances between centers in a longitudinal direction). An interference of light propagating in each of the cores 1a is then suppressed, and a crosstalk can be reduced to equal to or less than -30 decibels.
[0024] The multi-core optical fiber 1 includes 10,000 cores 1a, and has a possibility of achieving a remarkably large-capacity optical transmission that has never been able to be achieved. The manufacturing method according to the first embodiment as will be explained below can provide the multi-core optical fiber 1 more easily than the conventional method, and includes a preparing process, a first elongating process and a second elongating process. The manufacturing method will be explained below with respect to a case of using different kinds of cores 1a and setting a distance between centers of the cores 1a to 50 micrometers at least, and a case of using the same kind of cores 1a and setting a distance between centers of the cores 1a to 80 micrometers at least.
Consequently, it would have been obvious to one of ordinary skill in the art to modify and combine Thomson’s embodiments and related methods of manufacturing to disclose an apparatus (1) for guiding light from an input side (5) to an output side (6), comprising an input waveguide (3) at the input side (5) formed by at least two multi-mode fibres (7), an output waveguide (4) at the output side (7) formed by a single multi-mode fibre (5) and a photonic lantern (2) optically connecting the at least two multi-mode fibres (7) of the input waveguide to the single multi-mode fibre (8) of the output waveguide, said photonic lantern (2) is being designed such that, light transmitted by light guiding cores (9) of the at least two multi-mode fibres (7) of the input waveguide (3) is coupled into a light guiding core (10) of the single multi-mode fibre (8) of the output waveguide (4) and propagates through the light guiding core (10) of the single multi-mode fibre (8) of the output waveguide (4) and that claddings (11) surrounding the light guiding cores (9) of the at least two multi-mode fibres (7) of the input waveguide (3) are tapered down until they do at least almost not confine light; because the resulting configuration and method would facilitate ‘large-capacity image transmission and spatial multiplexing transmission.’ Mukasa, paragraph [0005].
Regarding device claims 2-11, which depend upon claim 1, independent method claim 12, and dependent method claims 13-16, it would have been obvious to one of ordinary skill in the art to modify and combine Thomson in view of Mukasa’s embodiments (and related methods of manufacturing and/or use), as applied in the rejection of claim 1, to disclose
2. Apparatus according to claim 1, characterized in that the at least two multi-mode fibres (7) of the input waveguide are located inside a capillary (12). Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
3. Apparatus according to claim 2, characterized in that the capillary (12) forms the cladding of the single multi-mode fibre (8) of the output waveguide (4). Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
4. Apparatus according to claim 2, characterized in that the capillary (12) comprises fluorine doped silica glass. Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
5. Apparatus according to claim 1, characterized in that the multi-mode fibres (7) of the input waveguide (3) are arranged in a close packed arrangement in relation to a cross-sectional plane of the input waveguide (3). Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
6. Apparatus according to claim 1, characterized in that a ratio of a diameter of the light guiding core (9) of at least one of the multi-mode fibres (7) of the input waveguide (3) to its cladding (11) is between 1.05 and 1.15, preferably 1.1. Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
7. Apparatus according to claim 1, characterized in that the input waveguide (3) comprises 58 to 62 multi-mode fibres (7). Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
8. Apparatus according to claim 1, characterized in that the photonic lantern (2) is designed such that the diameter of the light guiding core (9) of at least one of the multi-mode fibres (7) of the input waveguide (3) tapers down by 94.5 to 95.5%. Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
9. Apparatus according to claim 1, characterized in that the light guiding core (9) of at least one multi-mode fibre (7) of the input waveguide (3) and/or the light guiding core (10) of the single multi-mode fibre (8) of the output waveguide (4) comprise pure silica. Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
10. Apparatus according to claim 1, characterized in that the refractive index of the light guiding core (9) of at least one multi-mode fibre (7) of the input waveguide (3) and/or the refractive index of the single multi-mode fibre (8) of the output waveguide (4) is 1.440 to 1.448, preferably 1.444 at a wavelength within a range of 1450 to 1650 nm, in particular at a wavelength of approximately or accurately 1550 nm. Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
11. Apparatus according to claim 2, characterized in that the refractive index of the capillary (12) is 1.425 to 1.430, preferably 1.428 at a wavelength within a range of 1450 to 1650 nm, in particular at a wavelength of approximately or accurately 1550 nm. Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
12. Method for producing a photonic lantern (2) suitable for an apparatus for guiding light from an input side (5) to an output side (6) comprising the steps of: providing at least two multi-mode fibres (7) comprising a light guiding core (9) and a cladding (11) surrounding the light guiding core (9), stacking the at least two multi-mode fibres (7) inside a capillary (12), heating and drawing the capillary (12) together with the multi-mode fibres (7) in such a way, (a) that the light guiding cores (9) of the at least two multi-mode fibres (7) become a light guiding core (10) of a single multi-mode fibre (8), at which the capillary (12) building the cladding of said single multi-mode fibre (8) and (b) that claddings (11) surrounding the light guiding cores (9) of the at least two multi-mode fibres (7) when stacked inside the capillary (12) are tapered down until they do at least almost not confine light. Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
13. Method according to claim 12, characterized in that the at least two multiple multi-mode fibres (7) comprising a light guiding core (9) and a cladding (11) surrounding the light guiding core (9) are stacked together in a close packed arrangement inside the capillary (12). Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
14. Method according to claim 12, characterized in that the diameter of the light guiding cores (9) of the at least two multi-mode fibres (7) are tapered down in such a way that a resulting diameter is 4.5 to 4.6% of the diameter before tapering. Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
15. Use of an apparatus (1) according to claim 1 for coupling light from multiple telescopes into a single spectrograph, for medical endoscopy and/or for guiding light from multiples laser sources to a laser cutting tool. Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
16. Use of a photonic lantern produced according to claim 12 for coupling light from multiple telescopes into a single spectrograph, for medical endoscopy and/or for guiding light from multiples laser sources to a laser cutting tool. Thomson, figures 1 and 2, and related text and figures; See Thomson – Selected Text; Mukasa, figures 1-8, and related text; See Mukasa – Selected Text.
because the resulting configurations and methods would facilitate ‘large-capacity image transmission and spatial multiplexing transmission.’ Mukasa, paragraph [0005].
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PETER RADKOWSKI whose telephone number is (571)270-1613. The examiner can normally be reached on M-Th 9-5. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Thomas Hollweg, can be reached on (571) 270-1739. The fax phone number for the organization where this application or proceeding is assigned is (571) 273-8300.
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/PETER RADKOWSKI/Primary Examiner, Art Unit 2874