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 .
Information Disclosure Statement
Information disclosure statement filed 9/18/2024 has been considered.
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.
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.
Claim(s) 1-4, 7-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN105204113A (hereinafter “CN’113”).
Regarding claim 1, CN’113 discloses a polarization controller based on on-chip mode conversion, comprising: an input end-face coupler (not explicitly labeled, but inherently present in the device of CN’113, since a light beam must be inputted to the end face of the device shown in Fig. 1), an input polarization-dependent mode converter (104), a multi-mode 1 x 1 Mach-Zehnder interferometer with a 1x2 multi-mode beam splitter (106+102+108), an output polarization-dependent mode converter (109), and an output end-face coupler (not explicitly labeled, but inherently present in the device of CN’113, since a light beam must be outputted from the end face of the device shown in Fig. 1), wherein an output end of the input end-face coupler is connected to an input end of the input polarization-dependent mode converter output end of the input polarization-dependent mode converter is connected to an input end of the multi-mode 1x1 MZI, an output end of the multi-mode 1x1 MZI is connected to an input end of the output polarization-dependent mode converter, and an output end of the output polarization-dependent mode converter is connected to the output end-face coupler; and the input end and the output end of the multi-mode 1x1 MZI are respectively connected to the input polarization-dependent mode converter and the output polarization-dependent mode converter through a multi-mode beam splitter and a polarization-dependent mode converter (Fig. 1).
However, CN’113 does not explicitly disclose the use of an input phase shifter and an output phase shifter, in the manner claimed in the present application. Nevertheless, the use of phase shifters is well known and common in the art. One of ordinary skill in the art would readily recognize the advantage of using such phase shifters since, they provide precise, tunable control over the relative phase between orthogonal polarization components, enabling accurate polarization state adjustment with high stability and compact integration. Therefore, it would have been obvious to a person of ordinary skill in the art before the filing date of the present application to modify the device of CN’113 to have an input phase shifter and an output phase shifter, in the manner claimed in the present application.
Regarding claim 2, CN’113 discloses that the multi-mode 1x1 MZI comprises an input-end 1x2 multi-mode beam splitter (106), an input-end S-shaped bent waveguide (106), a phase shifter (107), an output-end S-shaped bent waveguide (108), and an output-end 2x1 multi-mode beam combiner (108); wherein the output-end 2x1 multi-mode beam combiner and the input-end 1x2 multi-mode beam splitter are symmetrically arranged at an end portion of the multi-mode 1x1 MZI (Fig. 1); an input end of the input-end 1x2 multi-mode beam splitter is connected to the input polarization-dependent mode converter (104); and an output end of the output-end 2x1 multi-mode beam combiner is connected to the output polarization-dependent mode converter (109). As such, the claimed limitations of claim 2 would be also rendered obvious when the device of CN’113 is modified as discussed regarding claim 1.
Regarding claim 3, CN’113 discloses wherein a core region of the input polarization-dependent mode converter/ the output polarization-dependent mode converter (104, 109) is a graded tapered waveguide with a vertical asymmetry cross-section, the graded tapered waveguide widens gradually, a narrow end of the graded tapered waveguide is connected to the input phase shifter/ the output phase shifter, and a wide end of the graded tapered waveguide is connected to the multi-mode 1x1 MZI (Fig. 1); and the width of the narrow end and the width of the wide end of the graded tapered waveguide span the width of hybridization region between TMo and TE1 modes (page 3 of the English translation of CN’113).
Regarding claim 4, CN’113 renders obvious the polarization controller of claim 1 as discussed above. In addition, CN’113 discloses wherein the graded tapered waveguide with the vertical asymmetry cross-section is of a tapered ridge waveguide structure (Fig. 3; page 4 of the English translation of CN’113). However, CN’113 does not explicitly disclose a waveguide structure with unequal refractive indices for upper and lower cladding layers, or a waveguide structure with a non-perpendicular inclined sidewall, as claimed in the present application. On the other hand, having a waveguide structure with unequal refractive indices for upper and lower cladding layers or a waveguide structure with a non-perpendicular inclined sidewall is well known and common in the art. Such features would have been readily recognized as advantageous and desirable since they allow for tailoring of mode field distribution and confinement factor. A higher-index upper cladding can reduce leakage at the top interface, while a lower-index lower cladding can strengthen confinement at the substrate interface. Therefore, it would have been obvious to a person of ordinary skill in the art before the filing of this application to modify the device of CN’113 to have a waveguide structure with unequal refractive indices for upper and lower cladding layers or a waveguide structure with a non-perpendicular inclined sidewall in the manner claimed in the present application.
Regarding claim 7, CN’113 renders obvious the polarization controller of claim 1 as discussed above. However, it does not explicitly disclose input/output end-face coupler adopts an inverted cone design in the manner claimed in the present application. On the other hand, such gradually widening/ narrowing input-output couplers are well known and common in the art. One of ordinary skill would readily recognize the advantage having such optical couplers since they allow for low-loss adiabatic coupling of optical beams for high fidelity waveguide device. Therefore, it would have been obvious to a person of ordinary skill in the art before the filing date of the present application to modify the device of CN’113 to have input/output end-face couplers adopting an inverted cone design in the manner claimed in the present application.
Regarding claim 8, CN’113 renders obvious the polarization controller of claim 1 as discussed above. In addition, CN’113 discloses the input/output coupler, input/output polarization dependent mode coupler, the multi-mode 1x1 MZI are all integrated on a same silicon substrate (Fig. 1). As such, the claimed limitations of claim 8 are also rendered obvious when the device of CN’113 is modified as discussed above regarding claim 1.
Claim(s) 5-6 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN’113 in view of JP6069439B1 (hereinafter “JP’439”).
Regarding claim 5, CN’113 renders obvious the polarization controller of claim 1 as discussed above. In addition, CN’113 discloses that its device is realized by adiabatic couplers. However, it does not explicitly disclose that the 1x2 multi mode beam splitter and combiner are Y-branch structure comprising three adiabatically evolved waveguides, wherein one adiabatically evolved waveguide is located in a middle between the other two adiabatically evolved waveguides to serve as a central waveguide, the other two adiabatically evolved waveguides on two sides of the central waveguide being symmetrical beam splitting waveguides in the manner claimed in the present application. On the other hand, such Y branch structure is known in the art. For example, JP’439 discloses a Y branch coupling structure comprising three adiabatically evolved waveguides, wherein one adiabatically evolved waveguide is located in a middle between the other two adiabatically evolved waveguides to serve as a central waveguide, the other two adiabatically evolved waveguides on two sides of the central waveguide being symmetrical beam splitting waveguides (Fig. 1). One of ordinary skill in the art would readily recognize such features as advantageous and desirable since it would allow for low loss, highly effective multimode splitting and combining branch waveguide structure. Therefore, it would have been obvious to a person of ordinary skill in the art before the filing date of the present application to modify the device of CN’113 to have the 1x2 multi mode beam splitter and combiner that are Y-branch structure comprising three adiabatically evolved waveguides, wherein one adiabatically evolved waveguide is located in a middle between the other two adiabatically evolved waveguides to serve as a central waveguide, the other two adiabatically evolved waveguides on two sides of the central waveguide being symmetrical beam splitting waveguides in the manner claimed in the present application.
Regarding claim 6, neither CN’113 nor JP’439 explicitly discloses wherein a wide end of the central waveguide is connected to a wide end of a graded tapered waveguide, and a width of the wide end of the graded tapered waveguide is identical to a width of the wide end of the central waveguide; and wide ends of the two symmetrical beam splitting waveguides are respectively connected to respective S-shaped bent waveguides, in the manner claimed in the present application. On the other hand, such features would have been a mere design choice that does require any additional teachings or insights outside the scope of invention disclosed by CN’113 and JP’439. One of ordinary skill in the art would readily recognize the advantage of having the width of the wide end of the graded tapered waveguide being identical to the width of the wide end of the central waveguide since such dimension would allow for maximum light coupling without excess light leak into the cladding layers of the waveguide. Therefore, it would have been obvious to a person of ordinary skill in the art before the filing date of the present application to modify the device of CN’113 and JP’439 to have a wide end of the central waveguide is connected to a wide end of a graded tapered waveguide, and a width of the wide end of the graded tapered waveguide is identical to a width of the wide end of the central waveguide; and wide ends of the two symmetrical beam splitting waveguides are respectively connected to respective S-shaped bent waveguides, in the manner claimed in the present application.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SUNG H PAK whose telephone number is (571)272-2353. The examiner can normally be reached M-F: 7AM- 5PM.
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/SUNG H PAK/Primary Examiner, Art Unit 2874
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