Prosecution Insights
Last updated: October 25, 2026
Application No. 18/421,323

CAVITY FOR INTENSITY BUILD UP OF MULTIPLE LASERS

Final Rejection §103
Filed
Jan 24, 2024
Priority
Jan 24, 2023 — provisional 63/440,735
Examiner
SAHLE, MAHIDERE S
Art Unit
2872
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
California Institute of Technology
OA Round
2 (Final)
80%
Grant Probability
Favorable
3-4
OA Rounds
0m
Est. Remaining
93%
With Interview

Examiner Intelligence

Grants 80% — above average
80%
Career Allowance Rate
910 granted / 1144 resolved
+11.5% vs TC avg
Moderate +13% lift
Without
With
+13.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
41 currently pending
Career history
1199
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
64.7%
+24.7% vs TC avg
§102
26.6%
-13.4% vs TC avg
§112
4.6%
-35.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1144 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 . Examiner’s Comments In view of the amendments, the prior objection to claim 15 is withdrawn. Claim Objections Claim 1 is objected to because of the following informalities: line 6 recites “smaller than and less than 15% smaller than” and line 14 recites “a an intensity distribution”. Appropriate correction is required. Claim 10 is objected to because of the following informalities: line 3 recites “overlap at- a center and middle”. Appropriate correction is required. Claim 16 is objected to because of the following informalities: line 1 recites “an cavity”, line 4 recites “that smaller than and less than 15% smaller than”, line 10 recites “form a circle on the mirror” without specifying which mirror or if both mirrors, and line 11 recites “the circulating laser beams” to reference the reflected laser beams. Appropriate correction is required. Claim 19 is objected to because of the following informalities: line 10 recites “smaller than and less than 15% smaller than”. Appropriate correction is required. 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. 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. Claims 16 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (WO 2019/007175 A11), hereinafter “Chen”, in view of Plaessmann et al. (USP No. 5,615,043), hereinafter “Plaessmann”. Regarding claim 16, Chen discloses a method of making an cavity (see Fig. 1), comprising: positioning a first concave mirror (103) having a focal length (Pg. 2, Line 22 of the translation provided); positioning a second concave mirror (104) having the focal length and an entry hole (101) (see Fig. 1, Pg. 2, Lines 22-23), at a distance from the first mirror (103) that smaller than and less than 15 % smaller than four times the focal length (Pg. 2, Lines 24-25 “0<d<2f or 2f<d<4f”); aligning the optical axis of the two mirrors facing each other (see Fig. 1), optionally allowing for a misalignment (see Fig. 1, an optional step is not a required step); launching a divergent laser beam through the entry hole (101) so that the laser beam reflects back from the first mirror (103) to a position just touching the entry hole and the subsequent reflected positions of the laser beam form a circle on the mirror (see Figs. 1, 2, Pg. 2, Lines 20-27). Chen discloses the claimed invention but does not specify and adjusting a focus of the laser beam so that the circulating laser beams within the cavity overlap with each other and form an intensity distribution on the mirrors and on cross sections along the length of the cavity. In the same field of endeavor, Plaessmann discloses and adjusting a focus of the laser beam so that the circulating laser beams within the cavity overlap with each other and form an intensity distribution on the mirrors and on cross sections along the length of the cavity (Col. 5, Lines 4-8, 66 – Col. 6, Line 13). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the method of Chen with and adjusting a focus of the laser beam so that the circulating laser beams within the cavity overlap with each other and form an intensity distribution on the mirrors and on cross sections along the length of the cavity of Plaessmann for the purpose of providing a laser amplifier that is efficient and cost-effective (Col. 5, Lines 2-3). Regarding claim 17, Chen further discloses further comprising providing instructions for the positioning, aligning, the launching, and the adjusting (see Fig. 1, Pg. 2, Lines 20-27). Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Chen (WO 2019/007175 A1) in view of Plaessmann (USP No. 5,615,043) as applied to claim 17 above, and further in view of Suzuki et al. (USP No. 6,487,003), hereinafter “Suzuki”. Regarding claim 18, Chen and Plaessmann disclose the claimed invention but do not specify further comprising using the cavity to build up the power of the electromagnetic radiation for interacting with material, wherein the material does not substantially reflect or absorb the electromagnetic radiation. In the same field of endeavor, Suzuki discloses further comprising using the cavity to build up the power of the electromagnetic radiation for interacting with material, wherein the material does not substantially reflect or absorb the electromagnetic radiation (see Figs. 2, 3, Col. 5, Lines 4-19). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the method of Chen and Plaessmann with further comprising using the cavity to build up the power of the electromagnetic radiation for interacting with material, wherein the material does not substantially reflect or absorb the electromagnetic radiation of Suzuki for the purpose of providing the desired optical treatment (Col. 5, Lines 17-19). Furthermore, it has been held that a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus satisfying the claimed structural limitations. Ex parte Masham, 2 USPQ2d - 164 7 (1987). REASONS FOR ALLOWANCE Claims 1-15 and 19-21 are allowed. The following is an examiner’s statement of reasons for allowance: none of the references, alone or in combination, disclose or teach the cavity and kit for making an optical cavity specifically comprising first and second concave mirrors having a focal length and facing each other at a distance that is less than 15% smaller than four times the focal length, a radial distance of an entry hole from the center of the second concave mirror is smaller than ½ of the mirror radius and larger than the minimum distance required for at least 10 passes of the laser beam reflecting between the mirrors, and the laser beam is a gaussian beam that is divergent at a first one of the passes so that all of the passes overlap to buildup power of the electromagnetic radiation in an intensity distribution in cross-sections perpendicular to the length of the cavity as is disclosed in independent claims 1 and 19. Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.” Response to Arguments Applicant’s arguments with respect to claims 16-18 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 MAHIDERE S SAHLE whose telephone number is (571)270-3329. The examiner can normally be reached Monday-Thursday 8:00 AM to 5:00 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, Ricky Mack can be reached at 571 272-2333. 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. /MAHIDERE S SAHLE/Primary Examiner, Art Unit 2872 10/10/2026 1 English translation is attached
Read full office action

Prosecution Timeline

Jan 24, 2024
Application Filed
Apr 29, 2026
Non-Final Rejection mailed — §103
Jul 28, 2026
Response Filed
Oct 14, 2026
Final Rejection mailed — §103 (current)

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

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Prosecution Projections

3-4
Expected OA Rounds
80%
Grant Probability
93%
With Interview (+13.1%)
2y 7m (~0m remaining)
Median Time to Grant
Moderate
PTA Risk
Based on 1144 resolved cases by this examiner. Grant probability derived from career allowance rate.

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