Prosecution Insights
Last updated: October 02, 2026
Application No. 18/275,821

TWO-DIMENSIONAL PHOTONIC-CRYSTAL SURFACE-EMITTING LASER

Final Rejection §103
Filed
Aug 04, 2023
Priority
Feb 24, 2021 — JP 2021-027908 +1 more
Examiner
NELSON, HUNTER JARED
Art Unit
2828
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Kyoto University
OA Round
2 (Final)
39%
Grant Probability
At Risk
3-4
OA Rounds
7m
Est. Remaining
63%
With Interview

Examiner Intelligence

Grants only 39% of cases
39%
Career Allowance Rate
12 granted / 31 resolved
-29.3% vs TC avg
Strong +24% interview lift
Without
With
+24.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
50 currently pending
Career history
72
Total Applications
across all art units

Statute-Specific Performance

§103
66.7%
+26.7% vs TC avg
§102
11.2%
-28.8% vs TC avg
§112
21.9%
-18.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 31 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 . Response to Amendment Examiner acknowledges the cancellation of claim 6. Claims 2-4 stand as objected. No new claims have been added. Response to Arguments Applicant's arguments filed 07/10/2026 have been fully considered but they are not persuasive. Examiner notes that the reference of Noda is relied upon to anticipate the limitations regarding a radiation coefficient difference as shown in Noda Fig. 7A and disclosed in paragraphs [0058-0060] of Noda as previously stated in the Office Action dated 04/30/2026. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). Examiner notes that Nagatomo is relied upon for the limitation of how the absorption coefficient is varied through variable thickness of the layer adjacent to the photonic crystal layer (i.e. variable distance between surfaces of the photonic crystal layer and reflection layer in Ohnishi) where Noda is relied upon for the actual radiation coefficient difference value. Therefore, the remarks against Nagatomo for failing to disclose the radiation coefficient difference is not taking in to account the teachings of Noda. Applicant states that there is no reasonable expectation of success for combining the applied references as required in MPEP § 2143.02. Noda discloses obtaining a desired absorption coefficient difference in paragraphs [0058-0060] in order to obtain desired laser oscillation in specific modes and output power. Nagatomo discloses a manner in which specific absorption coefficient values can be obtained through specific layer thicknesses adjacent to the photonic crystal layer as disclosed in paragraphs [0064-0066 and 0080]. Therefore, one would expect a reasonable expectation of success as Noda is disclosing a desire for a specified absorption coefficient difference and Nagatomo is disclosing a specific manner in which a desired absorption coefficient value can be reached in a photonic crystal layer. Further, Nagatomo also discloses in Fig. 2 and paragraph [0087] that different regions of a same photonic crystal layer can be selected so as to have differing radiation coefficients. (see Nagatomo Fig. 2 and paragraph [0087]) Drawings The drawings were received on 07/10/2026. These drawings are acceptable. The previous objection to the drawings has been withdrawn in light of the drawings filed 07/10/2026 and the cancellation of claim 6. Specification Examiner acknowledges the amendments made to the specification filed 07/10/2026. Allowable Subject Matter Claim 2 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Claims 3 and 4 are also objected due to their dependency to claim 2. The following is a statement of reasons for the indication of allowable subject matter: Claim 2 discloses limitations of the modified refractive index regions arranged on a square lattice, which is disclosed in Fig. 9 of Ohnishi with modified refractive index regions [432] arranged on a square lattice (Ohnishi Para. [0090]). Claim 2 further limits the radiation coefficient difference ▲av to be represented by formula (5) which shows a value of the radiation coefficient difference to be equated to a relationship of a non-Hermitian coupling coefficient µ, a value “R” equated to a relationship of one and two-dimensional coupling coefficient and an added phase θPC. Equation 5 also includes a diameter L of an inscribed circle in a range in which light emission occurs into the active layer. (see [Mathematical formula 5] in claim 2) US 20170256911 A1 (Noda) discloses a calculation of a threshold gain difference ▲a which is a value obtained by subtracting the threshold gain of a fundamental mode and a higher mode. Noda further discloses how changing a length [L] of a device structure and a length [Li] of an electrode changes the value of the threshold gain difference and therefore discloses that the threshold gain difference is dependent on an emission area of an active layer (Paras. [0003,0004,0058,0059]). Noda fails to disclose a relationship of the one and two-dimensional coupling coefficients, added phase, or non-Hermitian coupling coefficients in addition to the emission area to calculate a value of the threshold gain difference ▲a. US 20210184430 A1 discloses a relationship of one-dimensional and two-dimensional coupling coefficients depending on a structure of a photonic crystal layer. US 20210184430 A1 further discloses a dependence of a threshold gain on a material composition of a photonic crystal layer. US 20210184430 A1 also fails to disclose a relationship of the one and two dimensional coupling coefficients and a radiation coefficient difference that also depends on an emission area in an active layer. US 20190067907 A1 further discloses a value of a threshold gain difference that is dependent on a structure of a photonic crystal layer where a large device size is used to obtain the threshold gain difference value disclosed. US 20190067907 A1 does not disclosed the mathematical relationship defined in claim 2. 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. 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 1 is rejected under 35 U.S.C. 103 as being unpatentable over Ohnishi et al. (hereinafter Ohnishi) (US 20090279579 A1) in view of Noda et al. (hereinafter Noda) (US 20170256911 A1) and Nagatomo et al. (hereinafter Nagatomo) (US 20120269224 A1). Regarding claim 1, Ohnishi discloses in Fig. 8, A two-dimensional photonic-crystal surface-emitting laser [Fig. 8] (Para. [0090]) comprising: a) a two-dimensional photonic-crystal layer [43] (Para. [0090]) in which modified refractive index regions [432 Fig. 9] (Para. [0090]) having a refractive index different from a refractive index of a plate-like base material [431 Fig. 9] (Paras. [0019,0090]) are periodically disposed in the base material [431 Fig. 9] (Para. [0090]); b) an active layer [42] (Para. [0090]) provided on one surface side [above 43 Fig. 8] of the two-dimensional photonic-crystal layer [43] (Para. [0090]); and c) a reflection layer [45] (Para. [0092]) provided on another surface side [below 43 Fig. 8] of the two-dimensional photonic-crystal layer [43] or on a side of the active layer opposite to the two-dimensional photonic-crystal layer so as to be separated from the two-dimensional photonic-crystal layer, Ohnishi fails to disclose, wherein a distance between surfaces of the two-dimensional photonic-crystal layer and the reflection layer facing each other is set such that a radiation coefficient difference ▲av= (av1 – av0), which is a value obtained by subtracting a radiation coefficient av0 of a fundamental mode having a smallest loss from a radiation coefficient av1 of a first higher order mode having a second smallest loss among light amplified in the two- dimensional photonic-crystal layer, is 1 cm-1 or more. Noda discloses in Fig. 7A, a radiation coefficient difference [“threshold gain difference”] (Para. [0058]) ▲av= (av1 – av0) (Para. [0058]), which is a value obtained by subtracting a radiation coefficient av0 of a fundamental mode having a smallest loss from a radiation coefficient av1 of a first higher order mode having a second smallest loss among light amplified in the two- dimensional photonic-crystal layer (Paras. [0058-0060]), is 1 cm-1 or more [see Figs. 7A and 7B] (Paras. [0059,0060]) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the radiation coefficient value above 1cm-1 as shown in Noda into the device of Ohnishi for the purpose of easier laser oscillation in the fundamental mode. (Noda Para. [0058]) Ohnishi in view of Noda fails to disclose, wherein a distance between surfaces of the two-dimensional photonic-crystal layer and the reflection layer facing each other is set such that a radiation coefficient difference ▲av= (av1 – av0), which is a value obtained by subtracting a radiation coefficient av0 of a fundamental mode having a smallest loss from a radiation coefficient av1 of a first higher order mode having a second smallest loss among light amplified in the two- dimensional photonic-crystal layer, is 1 cm-1 or more. Nagatomo discloses in Fig. 1, Varying a thickness value of a layer [110] (Para. [0066]) adjacent to a photonic crystal layer [100] (Para. [0066]) to vary a value of a radiation coefficient (Paras. [0064-0066] It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the variation of thickness of a layer adjacent to the photonic crystal layer of the modified device of Ohnishi as shown in Nagatomo for the purpose of varying the radiation coefficient and controlling the uniformity of light intensity in the photonic crystal. (Nagatomo Paras. [0066,0067]) Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Ohnishi in view of Noda and Nagatomo as applied to claim 1 above, and further in view of Noda et al. (hereinafter Noda (387)) (WO 2017150387 A1). Examiner notes US 20190067907 A1 will be used for the claim mapping of Noda (387) for the remainder of the instant action. Regarding claim 5, Ohnishi in view of Noda and Nagatomo discloses the device outlined in the rejection of claim 1 above but fails to disclose, wherein each of the modified refractive index regions is made of a modified refractive index region pair in which a first modified refractive index region and a second modified refractive index region having different planar areas (Para. [0074]) are disposed apart from each other (Para. [0073]). Noda (387) discloses in Fig. 12, modified refractive index regions [1221B,1222B] (Para. [0073]) made of a modified refractive index region pair [122b] (Para. [0073]) in which a first modified refractive index region [1221B] (Para. [0073]) and a second modified refractive index region [1222B] (Para. [0073]) having different planar areas are disposed apart from each other. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the modified refractive index pair structure of Noda (387) as the photonic crystal structure of the modified device of Ohnishi for the purpose of obtaining a high threshold gain difference with a large device size. (Noda (387) Para. [0075]) Claims 7-10 are rejected under 35 U.S.C. 103 as being unpatentable over Ohnishi in view of Noda and Nagatomo as applied to claim 1 above, and further in view of Kanzaki et al (hereinafter Kanzaki) (US 20190219428 A1). Regarding claim 7, Ohnishi in view of Noda and Nagatomo discloses the device outlined in the rejection of claim 1 above and further discloses in Ohnishi Fig. 8, further comprising a first cladding layer [442 Fig. 8] (Para. [0092]) formed of a p-type semiconductor (Para. [0092]) or an n-type semiconductor and provided between the two- dimensional photonic-crystal layer [43] (Para. [0091]) and the reflection layer [45] (Para. [0092]), and a second cladding layer [441] (Para. [0090]) formed of a semiconductor having carriers whose polarity is opposite to that of the first cladding layer [442] (Paras. [0090,0092]) and provided on a side opposite to the reflection layer [45] side as viewed from the two-dimensional photonic-crystal layer [441 on opposite side of 43 from 45] (Para. [0090]), the first cladding layer [442] and the second cladding layer [441] being provided so as to sandwich the two-dimensional photonic crystal layer [43] and the active layer [42] (Para. [0090]) Examiner notes the interpretation of claim 7 is understood to be “further comprising a first cladding layer formed of a p-type semiconductor” The modified device of Ohnishi fails to disclose, wherein a product of a thickness and a refractive index of a layer other than the two-dimensional photonic-crystal layer between the first cladding layer and the second cladding layer is larger than a product of a thickness and a refractive index of the two- dimensional photonic-crystal layer. Kanzaki discloses in Fig. 5, wherein a product of a thickness and a refractive index of a guide layer [3] (Para. [0057]) other than the two-dimensional photonic-crystal layer [6] (Para. [0057]) between a first cladding layer [2] (Para. [0057]) and a second cladding layer [7] (Para. [0057]) is larger than a product of a thickness and a refractive index of the two- dimensional photonic-crystal layer [6] (Para. [0057]). Para. [0062] of Kanzaki discloses regions [6B] can include air (e.g. refractive index ≈ ). Therefore, the layer [6] has a lower product of thickness * refractive index than guide layer [3]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the guide layer with a higher thickness than the photonic crystal layer as shown in Kanzaki into the modified device of Ohnishi for the purpose of efficient containment of carriers and produced light. (Kanzaki Para. [0043]) Regarding claim 8, The modified device of Ohnishi discloses the device outlined in claim 7 above further discloses in Kanzaki Fig. 5, wherein a sum of thicknesses of layers [3] (Para. [0057]) other than the two-dimensional photonic-crystal layer [6] (Para. [0057]) between the first cladding layer and the second cladding layer is larger than a thickness of the two-dimensional photonic-crystal layer [6] (Para. [0057]) (See Fig. 5). Regarding claim 9, The modified device of Ohnishi discloses the device outlined in claim 7 above further discloses in Kanzaki Fig. 5, wherein a refractive index of the two-dimensional photonic-crystal layer [6] (Para. [0057]) is lower than a refractive index of a layer [3] (Para. [0057]) other than the two- dimensional photonic-crystal layer between the first cladding layer [2] (Para. [0057]) and the second cladding layer [7] (Para. [0057]). Para. [0062] of Kanzaki discloses regions [6B] can include air (e.g. refractive index ≈ ). Therefore, the layer [6] has a lower refractive index than guide layer [3]. Regarding claim 10, The modified device of Ohnishi discloses the device outlined in claim 7 above further discloses in Kanzaki Fig. 5, further comprising a guide layer [3] (Para. [0057]) between the first cladding layer [2] (Para. [0057]) and the second cladding layer [7] (Para. [0057]) on a side opposite to the two- dimensional photonic crystal layer [6] (Para. [0057]) as viewed from the active layer [4] (Para. [0057]). Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Examiner notes (US 20070177647 A1) which discloses a photonic crystal layer with differing hole depths. See PTO-892 form. THIS ACTION IS MADE FINAL. 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 HUNTER J NELSON whose telephone number is (571)270-5318. The examiner can normally be reached Mon-Fri. 8:30am-5:00 ET. 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, MinSun Harvey can be reached at (571) 272-1835. 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. /H.J.N./Examiner, Art Unit 2828 /XINNING(Tom) NIU/Primary Examiner, Art Unit 2828
Read full office action

Prosecution Timeline

Aug 04, 2023
Application Filed
Apr 30, 2026
Non-Final Rejection mailed — §103
Jul 10, 2026
Response Filed
Sep 11, 2026
Final Rejection mailed — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12731962
NARROW LINEWIDTH SEMICONDUCTOR LASER
4y 2m to grant Granted Sep 08, 2026
Patent 12719232
SEMICONDUCTOR DEVICE
3y 10m to grant Granted Aug 25, 2026
Patent 12719233
NITRIDE SEMICONDUCTOR LASER ELEMENT
3y 8m to grant Granted Aug 25, 2026
Patent 12706441
MICRO-RING LASER BANDWIDTH ENHANCEMENT WITH MICRO-RING RESONATOR
4y 0m to grant Granted Aug 11, 2026
Patent 12633724
VARIABLE-WAVELENGTH SURFACE EMISSION LASER
3y 11m to grant Granted May 19, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

Strategy Recommendation AI-generated — please review before filing

Get a prosecution strategy drawn from examiner precedents, rejection analysis, and claim mapping.
Typically takes 5-10 seconds — AI-generated, attorney review required before filing

Prosecution Projections

3-4
Expected OA Rounds
39%
Grant Probability
63%
With Interview (+24.5%)
3y 9m (~7m remaining)
Median Time to Grant
Moderate
PTA Risk
Based on 31 resolved cases by this examiner. Grant probability derived from career allowance rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month