Prosecution Insights
Last updated: April 19, 2026
Application No. 18/685,078

Optical Multiplex/Demultiplex Circuit and RGB Coupler

Non-Final OA §103
Filed
Feb 20, 2024
Examiner
WONG, TINA MEI SENG
Art Unit
2874
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
NTT, Inc.
OA Round
1 (Non-Final)
84%
Grant Probability
Favorable
1-2
OA Rounds
2y 5m
To Grant
98%
With Interview

Examiner Intelligence

Grants 84% — above average
84%
Career Allow Rate
909 granted / 1078 resolved
+16.3% vs TC avg
Moderate +14% lift
Without
With
+14.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
45 currently pending
Career history
1123
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
62.7%
+22.7% vs TC avg
§102
24.9%
-15.1% vs TC avg
§112
4.6%
-35.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1078 resolved cases

Office Action

§103
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 . Claim Rejections - 35 USC § 103 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 (i.e., changing from AIA to pre-AIA ) 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. 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(s) 1-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication 2019/0044300 to Takabayashi et al. In regards to claim 1, Takabayashi recites an optical multiplex/demultiplex circuit (Figure 1) which includes two waveguides, is made up of an asymmetric Mach-Zehnder interferometer (MZ) [0025] in which two arms (111 & 112) having different lengths [0028] are formed between two coupler portions, and multiplexes and demultiplexes light of different wavelengths, wherein a second waveguide core width of an arm through which light on a short wavelength side propagates is different than a first waveguide core width of the waveguide constituting the asymmetric MZ (Figure 2B & 2C; [0034-0035]). Although Takabayashi does not expressly recite wherein a second waveguide core width of an arm through which light on a short wavelength side propagates is larger than a first waveguide core width of the waveguide constituting the asymmetric MZ, Takabayashi does teach the two cores to be different widths as seen in Takabayashi’s Figures 2B and 2C. Since Takabayashi does not expressly recite one of the arms must have the larger core and only recites that the cores are different widths, it would have been obvious before the effective filing date to a person having ordinary skill in the art to have chosen a second waveguide core width of an arm through which light on a short wavelength side propagates is larger than a first waveguide core width of the waveguide constituting the asymmetric MZ for the purpose of varying the rate of change in the refractive index. [0035] In regards to claims 2 and 3, Takabayashi fails to expressly recite wherein the arm through which the light on the short wavelength side propagates includes a waveguide width expansion part having the second waveguide core width, and a waveguide width conversion part which is a tapered waveguide which connects the waveguide width expansion part and the waveguide having the first waveguide core width (claim 2) and wherein, in the two coupler portions, a waveguide core width of a waveguide serving as an arm through which the light on the short wavelength side propagates is made thicker to be equal to the second waveguide core width (claim 3). However, the inclusion of a width conversion part being tapered and to form the width of the waveguide core to be made equal to the second waveguide core would have been an obvious matter of common skill and design choice to a person having ordinary skill in the art at the time the invention was made. It would have been advantageous to include such features in order to prevent unwanted loss of light and ultimately a more efficient device. Therefore, it would have been obvious before the effective filing date to a person having ordinary skill in the art for the arm through which the light on the short wavelength side propagates includes a waveguide width expansion part having the second waveguide core width, and a waveguide width conversion part which is a tapered waveguide which connects the waveguide width expansion part and the waveguide having the first waveguide core width (claim 2) and in the two coupler portions, a waveguide core width of a waveguide serving as an arm through which the light on the short wavelength side propagates is made thicker to be equal to the second waveguide core width In regards to claim 4, Takabayashi recites a third waveguide core (121) width of an arm different from the arm through which the light on the short wavelength side propagates is thicker than the first waveguide core width and different from the second waveguide core width. [0030] In regards to claim 5, Takabayashi recites wherein the portions of the different arms having the third waveguide core width are provided in a straight line portion. (Figures 1 & 3) In regards to claims 6-8, Takabayashi recites the waveguide constituting the asymmetric MZ is a silica-based planar lightwave circuit [0034] and a directional coupler. Although Takabayashi does not expressly recite ZrO2 as a dopant, multiplexes/demultiplexes at least blue light and green light; and a mode coupler which multiplexes an output of the optical multiplex/demultiplex circuit and red light, Takabayashi does recite the filters in the device to be designed to separate the different wavelengths (red, blue, green) and shift the wavelengths as desired. (Abstract) Furthermore, choosing a known dopant such as ZrO2 to further alter the light signal in the waveguide to the desired output would have been a matter of common skill to one of ordinary skill in the art. since ZrO2 is a known dopant, readily available and allows for the manipulation of the light signal as desired. Therefore, it would have been obvious before the effective filing date to a person having ordinary skill in the art for there to have a ZrO2 as a dopant, and multiplexes/demultiplexes at least blue light and green light; and a mode coupler which multiplexes an output of the optical multiplex/demultiplex circuit and red light. References Cited The references cited made of record and not relied upon is considered pertinent to applicant’s disclosure. The documents submitted by applicant in the Information Disclosure Statement have been considered and made of record. Note attached copy of form PTO-1449. Regarding the lined through Foreign Patent document, the Foreign Patent document has not been submitted as required in accordance with 37 C.F.R. 1.98(a). It is additionally noted that Foreign Patent document #6 has been submitted twice. 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. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to TINA M WONG whose telephone number is (571)272-2352. The examiner can normally be reached M-F 8:30-5:30. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Uyen-Chau Le can be reached at (571) 272-2397. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /TINA WONG/Primary Examiner, Art Unit 2874
Read full office action

Prosecution Timeline

Feb 20, 2024
Application Filed
Mar 19, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
84%
Grant Probability
98%
With Interview (+14.1%)
2y 5m
Median Time to Grant
Low
PTA Risk
Based on 1078 resolved cases by this examiner. Grant probability derived from career allow rate.

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