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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on December 12, 2025 has been entered.
Response to Amendment
The Amendment filed December 12, 2025 has been entered.
Response to Arguments
Applicant's arguments filed December 12, 2025 have been fully considered but they are not persuasive.
Applicant argues on page 1 that : One or ordinary skill in the art would not modify Kikuchi in this way, as replacing the multiplexer 103 of Kikuchi with an Echelle grating multiplexer (of Sappy) would render Kikuchi unfit for its intended use. The multiplexer 103 (if configured as an Echelle grating multiplexer) would be unable to combine the wavelengths A-A6 into a common output as required by Kikuchi. It is pointed to the applicant Kikuchi’s multiplexer 103 is disclosed as a wavelength-multiplexing device that combines multiple optical channels into a single output for WDM transmission (see Kikuchi, Fig. 1 and ¶[0048]–[0054]). Sappey explicitly teaches that an Echelle grating can serve as a wavelength multiplexer/demultiplexer capable of combining multiple wavelengths into a common output port (US 2003/0026541 A1, Abstract; ¶[0015]–[0020]). Substituting Kikuchi’s multiplexer 103 with an Echelle grating multiplexer would therefore be a known equivalent substitution in the optical communications art, achieving the same overall function—combining multiple wavelengths into a single output—but with the well-known benefits of Echelle gratings (e.g., high resolution, compact form factor, and suitability for DWDM channel spacing).
The modification does not render Kikuchi inoperable; rather, it employs an alternative multiplexing technology to achieve the same multiplexing function in a predictable manner. Under KSR v. Teleflex, 550 U.S. 398 (2007), replacing one known multiplexing element with another known multiplexing element to achieve the same purpose is an obvious design choice, especially where both are capable of combining multiple wavelengths into a single output.
On page 1, Applicant argues that that Kikuchi is a fiber-based arrangement and “nowhere teaches a photonic integrated circuit,” let alone one incorporating first and second optical junctions and an Echelle grating multiplexer into such a circuit. The Examiner notes that while Kikuchi depicts fiber-based interconnections in certain embodiments, the underlying functional blocks (light sources, multiplexers, filters) are not limited to fiber-based implementations. It is well known in the optical communications field that these functions can be implemented in photonic integrated circuits (PICs) using planar waveguides, optical junctions, and integrated multiplexers. Sappey teaches an Echelle grating implemented in a planar waveguide structure (see Sappey fig. 1), and Kitagawa (US 2005/0151094 A1) teaches semiconductor light sources integrated on a chip with optical coupling elements (See Kitagawa [0017]-[0018]). One of ordinary skill in the art would have been motivated to integrate Kikuchi’s functional components—including the multiplexer—into a photonic integrated circuit to reduce size, improve stability, and eliminate fiber pigtail alignment issues, all of which are well-known advantages of PIC integration. The combination of Kikuchi’s WDM arrangement with Sappey’s planar Echelle grating multiplexer and Kitagawa’s integrated semiconductor light sources yields the claimed arrangement of first and second optical junctions connected via waveguides to an Echelle grating multiplexer within a photonic integrated circuit, with predictable results.
Applicant argues on page 3 that “Examiner acknowledges that Laude fails to teach first and second Echelle grating multiplexers, and instead argues that it would be obvious to replace the "X couplers 113 and 114" of "coupler 80" with Echelle grating multiplexers. One or ordinary skill in the art would not modify Laude in this way, as replacing the X couplers 113 and 114 of Laude with an Echelle grating multiplexer would render Laude unfit for its intended use. Specifically, coupler 80 is described as an "achromatic coupler", where light received at any of its inputs 81-84 is split between its four outputs 85-88. See Laude, col. 8, lines. 45-48 ("In operation, a signal at a given wavelength reaches one of the inputs of one of the couplers 80, 90 or 100 and is transmitted to four outputs of this 4x4 coupler with energy reduced by a factor of 4."). Replacing X coupler 113 with an Echelle grating multiplexer would not allow for light of a given wavelength, received at either of inputs 125, 126 to be split between outputs 85, 86. Similarly, replacing X coupler 114 with an Echelle grating multiplexer would not allow for light of a given wavelength, received at either of inputs 127, 128 to be split between outputs 87, 88. As a result, coupler 80 would no longer be operable as an achromatic couplers are required by Laude”. While Laude describes coupler 80 as an achromatic coupler (col. 8, lines. 45–48), this is merely one disclosed embodiment used to achieve wavelength-independent splitting in the NxN wavelength router. Laude’s broader disclosure is directed to optical routing based on wavelength-selective components (see col. 3, lines. 13–20). Nothing in Laude limits the invention to only achromatic couplers or precludes substitution of wavelength-selective devices where functional advantages are desired. One of ordinary skill in the art would recognize that coupler 80 could be implemented using alternative coupling/multiplexing technologies, including wavelength-selective devices such as Echelle gratings, to achieve different routing or multiplexing functionality.
Echelle grating multiplexers, as taught by Sappey (US 2003/0026541 A1), are well-known wavelength-selective devices capable of combining or separating optical channels over a defined wavelength range. Kitagawa (US 2005/0151094 A1) teaches semiconductor light sources emitting closely spaced wavelengths and combining them for analysis or transmission. Substituting Laude’s achromatic couplers with Echelle grating multiplexers in view of Sappey’s teaching would have been obvious to one of ordinary skill in the art seeking to integrate wavelength-selective multiplexing into a wavelength router, particularly where the light sources are as taught by Kitagawa.
The motivation for substitution comes from the desire to route, multiplex, or combine signals based on wavelength rather than purely splitting power evenly. This is consistent with the optical communication field’s trend toward dense wavelength division multiplexing (DWDM) for increased channel capacity — a problem explicitly addressed in Sappey and Kitagawa.
Applicant contends that replacing coupler 80’s internal X couplers with Echelle gratings would prevent splitting a given wavelength between multiple outputs. However, in the modified system, the Echelle gratings would serve a different function — namely, wavelength-selective multiplexing — rather than achromatic splitting. The modification does not render the device “inoperable” but rather changes the routing behavior to suit DWDM applications. In KSR v. Teleflex, 550 U.S. 398 (2007), the Supreme Court held that changing the function of a component to achieve predictable results in light of known technology is a valid basis for an obviousness rejection.
Both Laude’s couplers and Sappey’s Echelle gratings are optical coupling/multiplexing devices. Substituting one for the other in the context of wavelength routing is a predictable use of prior art elements according to their established functions. One of ordinary skill would expect that replacing achromatic couplers with Echelle gratings would yield a wavelength-selective NxN a predictable and desirable outcome in DWDM systems.
Laude does not teach away from wavelength-selective devices; rather, Laude’s disclosure of wavelength routing (via nxn routers) indicates that wavelength-dependent behavior is acceptable and even central to the invention. The use of achromatic couplers in one embodiment does not preclude the use of wavelength-selective multiplexers in another.
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.
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.
Claims 8-11 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Kikuchi (US20040208428A1) in view of Kitagawa (US20050151094), further in view of Sappey (US 20030026541 A1)
Regarding claim 8, Kikuchi teaches a light source module, comprising: a first semiconductor light source (106-1) operative to emit a first wavelength λ1 of light; a second semiconductor light source operative to emit a second wavelength λ3 of light (106-3) that is different than the first wavelength of light; a third semiconductor light source (106-2) operative to emit a third wavelength λ2 of light; a fourth semiconductor light source (106-4) operative to emit a fourth wavelength of light that is different than the third wavelength λ4 of light ([0059], [0064]); a first optical junction (101-1) operative to provide a first light output that includes the first and second wavelengths of light ([0059]); a second optical junction (101-2) operative to provide a second light output that includes the third and fourth wavelengths of light ; and a multiplexer (103) operative to provide a combined light output that includes the first, second, third, and fourth wavelengths of light ([0061], [0064]), but fails to disclose the second wavelength of light that is different than the first wavelength of light by less than four nanometers; the fourth wavelength of light that is different than the third wavelength of light by less than four nanometers, and the multiplexer operative to provide a combined light output that includes the first, second, third, and fourth wavelengths of light is an Echelle grating multiplexer, a photonic integrated circuit comprising: a first optical junction operative to provide a first light output that includes the first and second wavelengths of light; a second optical junction operative to provide a second light output that includes the third and fourth wavelengths of light; an Echelle grating multiplexer operative to provide a combined light output that includes the first, second, third, and fourth wavelengths of light; a first waveguide connecting the first optical junction to the Echelle grating multiplexer; and a second waveguide connecting the second optical junction to the Echelle grating multiplexer.
However, Kitagawa teaches a spectroscopy detection comprising an excitation light source having two or more semiconductor light sources ([0016]-[0017]) the second wavelength of light that is different than the first wavelength of light by less than four nanometers; the fourth wavelength of light that is different than the third wavelength of light by less than four nanometers ([0038] wavelength difference between the LD light sources 2 a to 2 d is set to 5 nm, but may be set to 1 nm or more).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kikuchi by incorporating the second wavelength of light that is different than the first wavelength of light by less than four nanometers; the fourth wavelength of light that is different than the third wavelength of light by less than four nanometers in order to provide increased power as taught by Kitagawa so the excitation light source capable of switching the wavelength with high precision can be realized ([0038]).
Kikuchi, when modified by Kitagawa, fails to disclose an Echelle grating multiplexer operative to provide a combined light output that includes the first, second, third, and fourth wavelengths of light, a photonic integrated circuit comprising: a first optical junction operative to provide a first light output that includes the first and second wavelengths of light; a second optical junction operative to provide a second light output that includes the third and fourth wavelengths of light; an Echelle grating multiplexer operative to provide a combined light output that includes the first, second, third, and fourth wavelengths of light; a first waveguide connecting the first optical junction to the Echelle grating multiplexer; and a second waveguide connecting the second optical junction to the Echelle grating multiplexer.
However, Sappey from the same field of endeavor, teaches an Echelle grating multiplexer ([0013], claim 6). Furthermore, Echelle grating multiplexer is well known in the art.
Therefore, it would have been obvious to someone of an ordinary skill in the art before the effective filing date of the claimed invention to modify Kikuchi and Kitagawa by incorporating an Echelle grating multiplexer operative to provide a combined light output that includes the first, second, third, and fourth wavelengths of light for a cost effective wavelength multiplexer/demultiplexer device ([0013]).
Kikuchi, when modified by Kitagawa and Sappey fails to disclose a photonic integrated circuit comprising: a first optical junction operative to provide a first light output that includes the first and second wavelengths of light; a second optical junction operative to provide a second light output that includes the third and fourth wavelengths of light; an Echelle grating multiplexer operative to provide a combined light output that includes the first, second, third, and fourth wavelengths of light; a first waveguide connecting the first optical junction to the Echelle grating multiplexer; and a second waveguide connecting the second optical junction to the Echelle grating multiplexer.
However, Kikuchi depicts fiber-based interconnections in certain embodiments, the underlying functional blocks (light sources, multiplexers, filters) are not limited to fiber-based implementations. It is well known in the optical communications field that these functions can be implemented in photonic integrated circuits (PICs) using planar waveguides, optical junctions, and integrated multiplexers. Sappey teaches an Echelle grating implemented in a planar waveguide structure (see Sappey, fig. 1]), and Kitagawa teaches semiconductor light sources integrated on a chip with optical coupling elements (See Kitagawa [0017]-[0018]).
Therefore, it would have been obvious to someone of an ordinary skill in the art before the effective filing date of the claimed invention to modify Kikuchi, Sappey and Kitagawa by incorporating a photonic integrated circuit comprising: a first optical junction operative to provide a first light output that includes the first and second wavelengths of light; a second optical junction operative to provide a second light output that includes the third and fourth wavelengths of light; an Echelle grating multiplexer operative to provide a combined light output that includes the first, second, third, and fourth wavelengths of light; a first waveguide connecting the first optical junction to the Echelle grating multiplexer; and a second waveguide connecting the second optical junction to the Echelle grating multiplexer with predictable results to reduce size, improve stability, and eliminate fiber pigtail alignment issues.
Regarding claim 9, Kikuchi, when modified by Kitagawa and Sappey teaches the light source module of claim 8, wherein: the first (101-1) and second (101-2) optical junctions are wavelength dependent multiplexers ([0059]: 101-1 and 101-2 are wavelength multiplexer).
Regarding claim 10, Kikuchi, when modified by Kitagawa and Sappey teaches the light source module of claim 8, where each of the first and second wavelengths of light are spaced apart by at least one nanometer (Kitagawa [0038]: a wavelength difference set to 5 nm, but may be set to 1 nm or more).
Regarding claim 11, Kikuchi, when modified by Kitagawa and Sappey teaches the light source module of claim 8, but fails to disclose wherein: the first optical junction is a first Mach-Zehnder interferometer; and the second optical junction is a second Mach-Zehnder interferometer.
However, multiplexing Mach-Zehnder interferometers are well known in the art as disclosed in Sakamoto ([0034] teaches the use of Mach-Zehnder interferometer as multiplexer).
Therefore, it would have been obvious to someone of an ordinary skill in the art before the effective filing date of the claimed invention to modify Kikuchi, Sappey and Kitagawa by incorporating the first optical junction is a first Mach-Zehnder interferometer; and the second optical junction is a second Mach-Zehnder interferometer to obtain predictable results of reducing insertion loss.
Regarding claim 13, Kikuchi, when modified by Kitagawa and Sappey, teaches the light source module of claim 8, but fails to disclose wherein: each of the first and second wavelengths of light is spectroscopically equivalent to each other.
However, Kitagawa teaches a spectroscopy detection comprising an excitation light source having two or more semiconductor light sources (Abstract), wherein: each of the first and second wavelengths of light is spectroscopically equivalent to each other ([0038] wavelength difference between the LD light sources 2 a to 2 d is set to 5 nm, but may be set to 1 nm or more. Since the separation of wavelength lights is very close (1nm), they are spectrospically equivalent to each other).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kikuchi, Sappey and Kitagawa by incorporating wherein: each of the first and second wavelengths of light is spectroscopically equivalent to each other so the excitation light source capable of switching the wavelength with high precision can be realized ([0038]).
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Kikuchi (US20040208428A1) in view of Kitagawa (US20050151094), further in view of Sappey (US 20030026541 A1), and further in view of Yonenaga (US 20140126905 A1)
Regarding claim 12, Kikuchi, when modified by Kitagawa and Sappey teaches the light source module of claim 8, but fails to disclose wherein: the first optical junction is operative as a first controllable switch; and the second optical junction is operative as a second controllable switch.
However, an optical junction operative as a controllable switch is well known in the art as disclosed in Yonenaga ([0071]).
Therefore, it would have been obvious to someone of an ordinary skill in the art before the effective filing date of the claimed invention to modify Kikuchi, Wu and Kitagawa by incorporating wherein: the first optical junction is operative as a first controllable switch; and the second optical junction is operative as a second controllable switch to obtain predictable results of better controlling light.
Claims 14-18 are rejected under 35 U.S.C. 103 as being unpatentable over Laude (US 5838848 A) in view of Kitagawa (US20050151094), further in view of Sappey (US 20030026541 A1).
Regarding claim 14, Laude teaches a light source module, comprising: a first set of light sources ( the optical inputs 81, 82 must come from light source) operative to emit a first set of wavelengths (each 81, 82 has a wavelength) (Col. 8, lines 12-15); a second set of light sources ( the optical inputs 83, 84 must come from light source) operative to emit a second set of wavelengths of light having (each 83, 84 has a wavelength); a first wavelength independent coupler (111) operative to receive light from each of the first set of semiconductor light sources and output: a first combined output (121) derived from the first of wavelengths of light and a second combined output (122, the coupler 80 comprises four 2.times.2 couplers reference numbers 111-114 each having two inputs; each of the couplers is an achromatic coupler with uniform distribution of energy between its outputs: The coupler combines the two inputs and splits them between the two outputs) derived from the first of wavelengths of light (Col. 8, lines 12-22); a second wavelength independent coupler (112) operative to receive light from each of the second set of semiconductor light sources (Col. 8, lines 12-22); and to output: a third combined output (123) derived from the second set of wavelengths of light; and a fourth combined output (124) derived from the second set of wavelengths of light(Col. 8, lines 12-22) ; a first multiplexer (113) operative to: receive the first combined output (121); receive the third combined output (123); and multiplex the first combined output and the second combined output to a first common output (85); and a second multiplexer (114) operative to: receive the second combined output (122); receive the fourth combined output (124); and multiplex the first combined output and the second combined output to a second common output (87), but fails to disclose a first set of semiconductor light sources, a second set of semiconductor light sources; a first set of wavelengths of light having different wavelengths, a second set of wavelengths of light having different wavelengths; the first multiplexer is Echelle grating and the second multiplexer is Echelle grating; different wavelengths are separated by less than four nanometers
However, Kitagawa, from the same field of endeavor, teaches a set of semiconductor light sources ([0016]-[0017]) a set of wavelengths of light having different wavelengths, wherein different wavelengths are separated by less than four nanometers (0038).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Laude by incorporating a first set of semiconductor light sources, a second set of semiconductor light sources; different wavelengths are separated by less than four nanometers in order to provide increased power as taught by Kitagawa so the excitation light source capable of switching the wavelength with high precision can be realized ([0038]).
Laude, when modified by Kitagawa, fails to disclose the first multiplexer is Echelle grating and the second multiplexer is Echelle grating.
However, Sappey, from the same field of endeavor, teaches an Echelle grating multiplexer ([0013], claim 6). Furthermore, Echelle grating multiplexer is well known in the art.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Laude and Kitagawa by incorporating the first multiplexer is Echelle grating and the second multiplexer is Echelle grating for a cost effective wavelength multiplexer/demultiplexer device ([0013]).
Regarding claim 15, Laude, when modified by Kitagawa and Sappy teaches the light source module of claim 14, wherein: the light source module comprises: a first waveguide (waveguide connecting output 121 to input 125) coupled between the first wavelength independent coupler and the first Echelle grating multiplexer (fig. 5); a second waveguide (waveguide connecting output 122 to input 127) coupled between the first wavelength independent coupler and the second Echelle grating multiplexer (fig. 5); a third waveguide (waveguide connecting output 123 to input 126) coupled between the second wavelength independent coupler and the first Echelle grating multiplexer (fig. 5); and a fourth waveguide (waveguide connecting output 124 to input 128) coupled between the second wavelength independent coupler and the second Echelle grating multiplexer (fig. 5).
Regarding claim 16, Laude, when modified by Kitagawa and Sappy, teaches the light source module of claim 14, wherein: the first output is transmitted to a first launch region (fig. 5: the area where light exits the coupler 113 is considered a launch region); and the second common output is transmitted to a second launch region (fig. 5: the area where light exits the coupler 114 is considered a launch region).
Regarding claim 18, Laude, when modified by Kitagawa and Sappy, teaches the light source module of claim 14, wherein the first set of wavelengths of light has different wavelengths separated by at least one nanometer (Kitagawa: [0038] wavelength difference between the LD light sources 2 a to 2 d is set to 5 nm, but may be set to 1 nm or more).
Regarding claim 19, Laude, when modified by Kitagawa and Sappy, teaches the light source module of claim 14, wherein: the second set of wavelengths of light has different wavelengths separated by at least one nanometer (Kitagawa: [0038] wavelength difference between the LD light sources 2 a to 2 d is set to 5 nm, but may be set to 1 nm or more).
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Laude (US 5838848 A) in view of Kitagawa (US20050151094), further in view of Sappey (US 20030026541 A1), and further in view of Wu (WO2020086744A1).
Regarding claim 20, Laude, when modified by Kitagawa and Sappy, teaches the light source module of claim 14, but fails to disclose wherein: the first wavelength independent coupler is a two by two multimode interferometer; and the second wavelength independent coupler is a two by two multimode interferometer.
However, Wu, from the same field of endeavor teaches wherein: the first wavelength independent coupler (302 (1,1)) is a two by two multimode interferometer; and the second wavelength independent coupler (302 (1,1)) is a two by two multimode interferometer (fig. 3, [0040]).
Therefore, 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 first wavelength independent coupler and the second wavelength independent coupler of Laude with the first two by two multimode interferometer and the second two by two multimode interferometer of Wu.
A person of ordinary skill in the art would have been motivated to do this in order to yield predictable results of providing low loss providing optical low-loss.
Conclusion
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/MOHAMED DOUMBIA/ Examiner, Art Unit 2877
/TARIFUR R CHOWDHURY/ Supervisory Patent Examiner, Art Unit 2877