Prosecution Insights
Last updated: April 19, 2026
Application No. 17/644,580

LOW-POWER PHOTONIC DEMODULATOR

Final Rejection §103
Filed
Dec 16, 2021
Examiner
FREY, KIMBERLY NEWMAN
Art Unit
2817
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
The Hong Kong University of Science and Technology
OA Round
4 (Final)
67%
Grant Probability
Favorable
5-6
OA Rounds
3y 7m
To Grant
48%
With Interview

Examiner Intelligence

Grants 67% — above average
67%
Career Allow Rate
10 granted / 15 resolved
-1.3% vs TC avg
Minimal -19% lift
Without
With
+-19.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
53 currently pending
Career history
68
Total Applications
across all art units

Statute-Specific Performance

§103
54.0%
+14.0% vs TC avg
§102
37.1%
-2.9% vs TC avg
§112
7.8%
-32.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 15 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. Claims 1 and 6-9 are rejected under 35 U.S.C. 103 as being unpatentable over Park; US 10141369 B2; 09/2016 in view of Han; US 2014/0124843 A1; 02/2013. Claim 1: Park discloses a photo-detector (#100) for detecting photons generated by a received light, the photo-detector comprising: a semiconductor substrate ( #102 ) doped with a first conductive type of dopant ( #106 p-type epitaxial layer ); two or more guided regions ( #120 and #122 ) formed in the semiconductor substrate ( #102 ) and doped with the first conductive type of dopant ( Col 5 lines 7 - 11 first conductivity type ); a photo sensing region ( #108 ) disposed between the two or more guided regions ( #120 and #122 ) for an impinging photon from the received light to generate photo carriers ( Fig 1. h+ and e- shown in the middle of the figure); and two or more detection regions ( #110 and #112 ) formed in the semiconductor substrate and doped with a second conductive type of dopant ( Col 5, lines 12 – 18, n-type well region ), wherein: the two or more guided regions are respectively connected to power sources ( Col 4, lines 60-62, “First and second guide voltages may be applied to the first and second field generating regions #120 and #122” ) to apply an electric potential across the two or more guided regions ( #120 and #122) for controlling a detectivity of the impinging photon ( Fig 1. h+ and e- shown in the middle of the figure ); and the photo sensing region ( #108 ) is provided to form at least a pn junction between the two or more guided regions ( Col 5, lines 16-18, “A PN junction may be formed between the first field generating region #120 and the first detection region #110” ) that is reverse biased ( Col 5, lines 60 – 62, “A reverse bias may be applied to the PN junction between the second field generating region #122 and the second detection region #112” ) so as to reduce or prevent a leakage path between the two or more guided regions ( #120 and #122). Park does not appear to disclose the photo sensing region comprises three or more sub-regions, wherein any two adjacent sub-regions are doped with different conductive type of dopants selected from the first and the second conductive type of dopants such that at least two pn junctions are formed for the three or more sub-regions, wherein the at least two pn junctions are configured to be reverse biased such that their depletion regions merge to fully deplete the photo sensing region. However, Han teaches the photo sensing region ( Fig. 2 photo sensor #100-1) comprises three or more sub-regions ( Fig. 2 #174, #172, and #114), wherein any two adjacent sub-regions are doped with different conductive type of dopants selected from the first ( [0045] The second doping region #174 may be doped with a high concentration of the first conductive type (for example p+ type)) and the second conductive type of dopants ( [0043] The first doping region #172 may form a pn-junction with the first conductive type semiconductor substrate #110 ) such that at least two pn junctions are formed ( [0046] a pnp junction structure including the p-type epilayer #114, the first doping region #172 and the second doping region #174 may result ) for the three or more sub-regions ( Fig. 2 #174, #172, and #114 ), wherein the at least two pn junctions are configured to be reverse biased ( Fig. 2 light-absorption control layer #160-1) such that their depletion regions merge to fully deplete the photo sensing region ( [0055] The light-absorption control layer #160-1 may control a depth at which light is absorbed in the first region Q1 of the photodiode region #170, a depth of photoelectric effect, and a depth of a pn-junction plane). It would have been obvious to one of ordinary skill in the art before the effective filing of the claimed invention, to utilize the teachings of Han with Park to have the photo sensing region comprises three or more sub-regions, wherein any two adjacent sub-regions are doped with different conductive type of dopants selected from the first and the second conductive type of dopants because each of the junctions has its own specific frequency behavior and size dependency. Claim 6: Park and Han disclose the photo-detector of claim 1 (as discussed above). Regarding claim 6, Park teaches further comprising an isolation region ( #130 blocking region) arranged to surround the two or more guided regions and the two or more detection regions, so as to isolate the two or more guided regions (#120 and #122 ) and the two or more detection regions ( #110 and #112 ) from the semiconductor substrate ( #102 ). Claim 7: Park and Han disclose the photo-detector of claim 6 (as discussed above). Regarding claim 7, Park teaches the isolation region ( #130 blocking region) is doped with the second conductive type of dopant (Col 7, lines 33 – 34, “the blocking region #130 may include a n-type impurity” ). Claim 8: Park and Han disclose the photo-detector of claim 1 (as discussed above). Regarding claim 8, Park teaches the two or more guided regions ( #120 and #122 ) comprise a first guided region ( #120) positioned immediately adjacent to a first side of the photo sensing region ( #108), and a second guided region ( #122 ) positioned immediately adjacent to a second side of the photo sensing region ( #108). Claim 9: Park and Han disclose the photo-detector of claim 1 ( as discussed above ). Regarding claim 9, Park teaches the first conductive type of dopant is a p-type doping ( Col 4, lines 46-48, “The substrate #102 may have a first conductivity type. For example, a p-type substrate” ), and the second conductive type of dopant is an n-type doping ( Col 5, lines 12 -18, “a second conductivity type. For example, a first n-type well region”) Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Park; US 10141369 B2; 09/2016 in view of Han; US 2014/0124843 A1; 02/2013 as applied to claim 1 above, and further in view of Radovanovic et al: “3-Gb/s Optical Detector in Standard CMOS for 850-nm Optical Communication,” IEEE Journal of Solid-State Circuits, September, 2005 Claim 4: Park and Han disclose the photo-detector of claim 1 (as discussed above), Neither Park nor Han appear to disclose the three or more sub-regions are arranged laterally alternating to form a lateral sequence of doping regions. However, Radovanovic teaches the three or more sub-regions (Fig 1, nwell, pwell, nwell), are arranged laterally alternating to form a lateral sequence (Fig 1, nwell, pwell, nwell) of doping regions. It would have been obvious to one of ordinary skill in the art before the effective filing of the claimed invention, to utilize the teachings of Radovanovic et al. with Park and Han to have the three or more sub-regions arranged laterally alternating to form a lateral sequence of doping regions because photodiode spread would be reduced by having multiple doped regions on a single device in a lateral layout. Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Park; US 10141369 B2; 09/2016 in view of Han; US 2014/0124843 A1; 02/2013 as applied to claim 1 above, and further in view of Wachmann; US 2023/0230985 A1; 06/2020. Claim 10: Park and Han disclose the photo-detector of claim 1 (as discussed above), Neither Park nor Han appear to disclose the first conductive type of dopant is an n-type doping, and the second conductive type of dopant is a p-type doping. However, Wachmann teaches the first conductive type ( [0008] a first type of electric conductivity ) of dopant is an n-type doping ( [0008] first type of electric conductivity is n-type ) , and the second conductive type of dopant is a p-type doping ( [0008] second type of electric conductivity is p-type ). It would have been obvious to one of ordinary skill in the art before the effective filing of the claimed invention, to utilize the teachings of Wachmann with Park and Han to have the first conductive type of dopant as an n-type doping, and the second conductive type of dopant as a p-type doping because this approach would create a superior PMOS device. Response to Arguments Applicant's arguments filed 12/23/2025 have been fully considered but they are not persuasive. The elements must be arranged as required by the claim, but this is not an ipsissimis verbis test, i.e., identity of terminology is not required. In re Bond, 910 F.2d 831, 15 USPQ2d 1566 (Fed. Cir. 1990). Note that, in some circumstances, it is permissible to use multiple references in a 35 U.S.C. 102 rejection. See MPEP § 2131.01. With respect to the first argument, concerning the inclusion of the epilayer in the sub-regions of the photodiode, Han states the following: [0035] The photodiode region 170 has a wide depletion region and a large depth through the low-concentration first conductive type epilayer 114. For this reason, collection of photocharges by a low-voltage photodiode and the photosensitivity of the device can be improved. With respect to the second argument, the light-absorption control layer controls the depth of a pn-junction plane which goes to the first lowermost surface 181 such that the depletion region is merged to fully deplete the photosensing region. It is shown in Fig. 2 that 181 is the lowermost surface of the first region at a depth of d1 from the surface. With respect to Claim 4, Radanovich illustrates in Fig. 1 a p+/nwell/p-substrate photodiode which satisfies the feature “wherein the three or more sub-regions are arranged laterally alternating to form a lateral sequence of doping regions.” Conclusion All claims are identical to or patentably indistinct from, or have unity of invention with claims in the application prior to the entry of the submission under 37 CFR 1.114 (that is, restriction (including a lack of unity of invention) would not be proper) and all claims could have been finally rejected on the grounds and art of record in the next Office action if they had been entered in the application prior to entry under 37 CFR 1.114. Accordingly, THIS ACTION IS MADE FINAL even though it is a first action after the filing of a request for continued examination and the submission under 37 CFR 1.114. See MPEP § 706.07(b). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KIMBERLY N FREY whose telephone number is (571)272-5068. The examiner can normally be reached Monday - Friday 7:30 am - 5 pm. 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, Marlon Fletcher can be reached at (571)272-2063. 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. /K.N.F./Examiner, Art Unit 2817 /MARLON T FLETCHER/Supervisory Primary Examiner, Art Unit 2817
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Prosecution Timeline

Dec 16, 2021
Application Filed
May 13, 2025
Non-Final Rejection — §103
Jul 09, 2025
Response Filed
Jul 30, 2025
Final Rejection — §103
Oct 03, 2025
Request for Continued Examination
Oct 11, 2025
Response after Non-Final Action
Oct 20, 2025
Final Rejection — §103
Dec 23, 2025
Request for Continued Examination
Jan 15, 2026
Response after Non-Final Action
Jan 26, 2026
Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 4 most recent grants.

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Prosecution Projections

5-6
Expected OA Rounds
67%
Grant Probability
48%
With Interview (-19.2%)
3y 7m
Median Time to Grant
High
PTA Risk
Based on 15 resolved cases by this examiner. Grant probability derived from career allow rate.

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