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
The prior art documents submitted by applicant in the Information Disclosure Statement(s) filed on 12/26/2024 have all been considered and made of record (note the attached copy(ies) of form PTO-1449).
Drawings
Six sheets of drawings were filed on 12/26/2025 and have been accepted by the examiner.
Inventorship
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.
Election/Restrictions
Applicant's election with traverse of species A and sub-species A-1 in the reply filed on March 13, 2026 is acknowledged. The traversal is on the ground(s) that there is no serious burden exists for the examiner to search and examine the restricted species and sub-species. This is not found persuasive because the optical waveguide interferometer for each species and sub-species have different designs and functions that are different among the species, as claimed.
The requirement is still deemed proper and is therefore made FINAL.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-3, 5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kawashima et al. (US 2013/0209111 A1, herein “Kawashima”).
Claim 1. Kawashima discloses an optical waveguide interferometer in Fig. 6A, comprising:
an input section (6DC1);
a middle section (6D1/6D2);
an output section (6DC2);
a first arm portion (6D2) having a first length that spans the input section, the middle section, and the output section; and
a second arm portion (6D1) having a second length that spans the input section, the middle section, and the output section;
wherein the first length of the first arm portion is less than the second length of the second arm portion; and wherein the second arm portion has a curved shape.
Claim 2. The optical waveguide interferometer of claim 1, wherein the first arm portion has a first bend at a transition of the first arm portion between the input section and the middle section; and wherein the second arm portion has a second bend at a transition of the second arm portion between the input section and the middle section.
3. The optical waveguide interferometer of claim 2, wherein the first arm portion has a third bend at a transition of the first arm portion between the middle section and the output section; and wherein the second arm portion has a fourth bend at a transition of the second arm portion between the middle section and the output section.
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Regarding claim 5, the first arm portion (6D2) has a first bend at a transition of the first arm portion between the input section (6DC1) and the middle section (6D1/6D2); and wherein the first arm portion extends in a straight line to a third bend at a transition between the middle section (6D1/6D2) and the output section (6DC2).
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.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Kawashima in view of Gerlach et al. (US 2003/0179972 A1, herein “Gerlach”).
Regarding claim 4, Kawashima discloses the invention of claim 3, but Kawashima is silent to:
a first angle is defined by the first arm portion after the first bend at the transition of the first arm portion between the input section and the middle section and the second arm portion at the transition of the second arm portion between the input section and the middle section after the second bend; and wherein a second angle is defined by the first arm portion before the third bend at the transition of the first arm portion between the middle section and the output section and the second arm portion before the fourth bend at the transition of the second arm portion between the middle section and the output section; and wherein the first angle and the second angle are equal.
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Gerlach teaches unequal arm Mach-Zehnder interferometric devices (10) as shown in Fig. 4 as a tunable filter in which the waveguide lengths of the filter’s elements are optimized for filter performance results (Para [0030]). The filter has fixed couplers (11) so that each coupler has a selected coupling angle θ. Each of the fixed couplers 11 and phase shifters 12 form Na actuator, which can affect the phase and coupling of the interferometric device (10) (Para [0033]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to recognize setting a constant coupling angle theta would be within the skill of a person of ordinary skill in the art. One motivation for modifying the coupler designs to be fixed is to reduce power because using fixed couplers require about half the thermo-optic actuation power (Para [0031]).
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Kawashima in view of Lipson et al. (US 2011/0102804 A1, herein “Lipson”).
Kawashima teach the invention of claim 1, but Kawashima does not teach a first span of the second arm portion in the middle section has a width that is different than a width of a second span of the second arm portion in the middle section.
Lipson teaches a passively thermally stabilized Mach-Zehnder interferometer (MZI 100) works on the principle that the guided mode have different effective mode index changes with temperature in the two arms of the MZI, induced by the different waveguide widths. The thermos-optic effect between the two interfering arms is balanced or adjusted while still maintaining a phase difference between the two arms as required by the filter specification (Para [0035]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to recognize different the waveguide widths between the two arms would induced a difference in effective index of the waveguides, thus inducing a phase difference in both arms. One would be motivated to induce a phase difference between the two arms in the MZI to design the MZI as an optical switch or optical modulator.
Conclusion
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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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Thomas A. Hollweg can be reached at (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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/ERIN D CHIEM/Examiner, Art Unit 2874
/THOMAS A HOLLWEG/Supervisory Patent Examiner, Art Unit 2874
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