Prosecution Insights
Last updated: April 19, 2026
Application No. 18/581,004

METHODS FOR FABRICATING OPTICAL METASURFACES

Non-Final OA §103
Filed
Feb 19, 2024
Examiner
KIM, RICHARD H
Art Unit
2871
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Wisconsin Alumni Research Foundation
OA Round
1 (Non-Final)
82%
Grant Probability
Favorable
1-2
OA Rounds
2y 5m
To Grant
87%
With Interview

Examiner Intelligence

Grants 82% — above average
82%
Career Allow Rate
734 granted / 900 resolved
+13.6% vs TC avg
Minimal +5% lift
Without
With
+5.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
25 currently pending
Career history
925
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
59.5%
+19.5% vs TC avg
§102
28.7%
-11.3% vs TC avg
§112
8.5%
-31.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 900 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) 1-12 and 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ossiander et al. (US 2025/0389868 A1) in view of Thio et al. (US 2003/0173501 A1). Re claim 1, Ossiander et al. discloses a method of fabricating an optical metasurface, the method comprising form a free-standing membrane (100) from a wafer and forming a metasurface pattern in the free-standing membrane to provide an optical metasurface comprising the free-standing membrane having defined therein (paragraph 0074), a periodic array of flow-through apertures (110), arranged according to the metasurface pattern, wherein the metasurface pattern is configured to confine incoming light within the flow-through apertures (paragraph 0034). Ossiander et al. does not disclose the method wherein the flow-through aperture has subwavelength dimensions. Thio et al. discloses a meta surface comprising subwavelength apertures (paragraph 0027). It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to employ the device comprising a meta surface comprising subwavelength apertures since one would be motivated to contribute to an enhanced electric field at the aperture (paragraph 0046). Re claim 2, Ossiander et al. does not disclose the method wherein the metasurface pattern is configured to support an optical mode characterized by an enhanced electric (E) field within the flow-through aperture. Thio et al. discloses a method wherein the metasurface pattern is configured to support an optical mode characterized by an enhanced electric (E) field within the flow-through aperture (paragraph 0046). It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to employ the method wherein the metasurface pattern is configured to support an optical mode characterized by an enhanced electric (E) field within the flow-through aperture since one would be motivated to maximize the optical throughput through the subwavelength aperture (paragraph 0046). Re claims 3-7, Ossiander et al. does not disclose the method wherein the enhanced E field of the optical mode throughout the flow-through apertures is greater than an enhanced E field of a photonic crystal guided mode throughout the flow-through apertures, wherein the optical mode is a bound state in the continuum (BIC) optical mode, wherein the BIC optical mode is a BIC optical mode, wherein the enhanced E field is capable of inducing vibrational strong coupling between a molecule present in the flow-through aperture and the optical mode and generating a polariton pair, wherein the enhanced E field is capable of inducing vibrational strong coupling between a molecule present in the flow-through aperture and the optical mode and generating a polariton pair, wherein the enhanced electric E field is at least 50 through the flow-through apertures. It would have been obvious to one having ordinary skill to employ the method wherein the enhanced E field of the optical mode throughout the flow-through apertures is greater than an enhanced E field of a photonic crystal guided mode throughout the flow-through apertures wherein the enhanced E field is capable of inducing vibrational strong coupling between a molecule present in the flow-through aperture and the optical mode and generating a polariton pair, wherein the enhanced electric E field is at least 50 through the flow-through apertures. Ossiander et al. discloses all the structural limitations of the claim. Therefore, the function of wherein “the enhanced E field of the optical mode throughout the flow-through apertures is greater than an enhanced E filed of a photonic crystal guided mode throughout the flow-through apertures wherein the enhanced E field is capable of inducing vibrational strong coupling between a molecule present in the flow-through aperture and the optical mode and generating a polariton pair, wherein the enhanced E field is capable of inducing vibrational strong coupling between a molecule present in the flow-through aperture and the optical mode and generating a polariton pair, wherein the enhanced electric E field is at least 50 through the flow-through apertures” would naturally flow from the structure. Furthermore, it would have been obvious to one having ordinary skill in the art to employ the method wherein “the enhanced E field of the optical mode throughout the flow-through apertures is greater than an enhanced E filed of a photonic crystal guided mode throughout the flow-through apertures wherein the enhanced E field is capable of inducing vibrational strong coupling between a molecule present in the flow-through aperture and the optical mode and generating a polariton pair, wherein the enhanced E field is capable of inducing vibrational strong coupling between a molecule present in the flow-through aperture and the optical mode and generating a polariton pair, wherein the enhanced electric E field is at least 50 through the flow-through apertures” since doing so combines prior art elements of the metasurface pattern with well-known optical modes in the art to obtain predictable result (KSR). Re claim 8, Ossiander et al. discloses the method wherein the incoming light is mid-infrared light (paragraph 0078). Re claim 9, Ossiander et al. discloses the method wherein the free-standing membrane is composed of a dielectric material selected from Group IV elements or Group III-V semiconductors (paragraph 0034). Re claim 10, Ossiander et al. discloses the method wherein the free-standing membrane (105) is free of conductive material. Re claim 11, Ossiander et al. discloses the method further comprising a resist layer having a resist pattern therein, the resist pattern corresponding to the metasurface pattern (paragraph 0082). Re claim 12, Ossiander et al. discloses the method further comprising applying the resist layer to a surface of the free-standing membrane (100) prior to forming the resist pattern therein (paragraph 0082). Re claim 17, Ossiander et al. discloses a device comprising a free-standing membrane (100) having defined therein, a period array of flow-through apertures (paragraph 0034), the flow-through apertures arranged according to a metasurface pattern (paragraph 0074), wherein the metasurface pattern is configured to confine incoming light within the flow-through apertures (paragraph 0034). Ossiander et al. does not disclose the device wherein the flow-through aperture has subwavelength dimensions. Thio et al. discloses a meta surface comprising subwavelength apertures (paragraph 0027). It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to employ the device comprising a meta surface comprising subwavelength apertures since one would be motivated to contribute to an enhanced electric field at the aperture (paragraph 0046). Claim(s) 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ossiander et al. and Thio et al. in view of Soer et al. (US 9,195,152 B2). Ossiander et al. does not disclose the device wherein the free-standing membrane has a thickness of no greater than 10 µm and the subwavelength dimensions are no greater than 10 µm. Soer et al. discloses a device wherein a free-standing membrane has a thickness of no greater than 10 µm and the subwavelength dimensions are no greater than 10 µm (col. 2, lines 40-49). It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to employ the device wherein the free-standing membrane has a thickness of no greater than 10 µm and the subwavelength dimensions are no greater than 10 µm since one would be motivated to obtain adjust the thickness of the free-standing membrane and the subwavelength dimensions according to the application of the device, such as to obtain a spectral purity filter. Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ossiander et al. and Thio et al. in view of Nicolaou et al. (“Enhanced detection limit by dark mode perturbation in 2D photonic crystal slap refractive index sensor”, Optics Express, December 13, 2023”). Ossiander et al. does not disclose the method wherein the metasurface pattern comprises a repeating metaunit comprising four apertures each having a radius r1 and arranged in a square array; and a central aperture having a radius r2, wherein r1>r2. Nicolaou et al. discloses a method wherein the metasurface pattern comprises a repeating metaunit comprising four apertures each having a radius r1 and arranged in a square array; and a central aperture having a radius r2, wherein r1>r2 (Fig. 5). It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to employ the method wherein the metasurface pattern comprises a repeating metaunit comprising four apertures each having a radius r1 and arranged in a square array; and a central aperture having a radius r2, wherein r1>r2 since one would be motivated by improving the detection limit by an order of magnitude with a simplified structure. Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ossiander et al. and Thio et al. in view of Sun et al. (“Strong coupling between quasi-bound states in the continuum and molecular vibrations in the mid-infrared,” Nanophotonics, August 9, 2022, pages 4221-4229, Vol. 11, No. 18). Ossiander et al. as modified Thio et al. do not disclose the method wherein the metasurface pattern comprises a repeating metaunit comprising two elliptical apertures tilted away from one another. Sun et al. discloses a method wherein the metasurface pattern comprises a repeating metaunit comprising two elliptical apertures tilted away from one another (Fig. 1). It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to employ the method wherein the metasurface pattern comprises a repeating metaunit comprising two elliptical apertures tilted away from one another since one would be motivated to realize strong coupling effect. Claim(s) 18 and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ossiander et al. and Thio et al. in view of Ysikloy et al., (“Ultrasensitive hyperspectral imaging of biodetection enabled by dielectric metasurfaces,” Nature Photonics, June 2019, pages 390-396). Ossiander et al. does not disclose the device comprising a sample delivery assembly configured to deliver a sample to at least one of the flow-through apertures, a light source configured to provide the incoming light; and a detector configured to detect light transmitted through the optical metal surface, wherein the sample delivery assembly is a component of, or is in fluid communication with, a microfluidic control system. Ysikloy et al. discloses a device comprising a sample to at least one of the flow-through apertures, a light source, configured to provide incoming light; and a detector configured to detect light transmitted through the metal surface (Fig. 1, ref. “Analyte”, “Sensor”, “CMOS”). It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to employ the device comprising a light source configured to provide the incoming light; and a detector configured to detect light transmitted through the optical metal surface since one would be motivated to analyze biological entities. Furthermore, employing a sample delivery assembly as a component of or in fluid communication with a microfluidic control system is well known in the art to precisely deliver a sample. Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ossiander et al. and Thio et al. in view of Hsu et al. (US 12,455,400 B2). Ossiander et al. does not disclose the device comprising an array of optical metasurfaces wherein each metasurface pattern of each optical metasurface has a different resonance wavelength λres and resonance bandwidth; a light source configured to provide the incoming light; and a detector configured to detect light transmitted through the array of metasurfaces. Hsu et al. discloses a device comprising an array of optical metasurfaces (18-1 - 18-4) wherein each metasurface pattern of each optical metasurface has a different resonance wavelength λres and resonance bandwidth (Fig. 3, ref. 18-1 – 18 -2; a light source (2) configured to provide the incoming light; and a detector (16) configured to detect light transmitted through the array of metasurfaces. The metasurfaces would have different wavelength λres and resonance bandwidth since the width and spacing of the structures of the metasurfaces are different between respective metasurfaces. It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to employ the device comprising an array of optical metasurfaces wherein each metasurface pattern of each optical metasurface has a different resonance wavelength λres and resonance bandwidth; a light source configured to provide the incoming light; and a detector configured to detect light transmitted through the array of metasurfaces since one would be motivated by obtaining a compact imaging system (abstract). Allowable Subject Matter Claim 13 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. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to RICHARD H KIM whose telephone number is (571)272-2294. The examiner can normally be reached M-F, 10 am-6:30 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, Michael Caley can be reached at 571-272-2286. 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. /RICHARD H KIM/Primary Examiner, Art Unit 2871
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Prosecution Timeline

Feb 19, 2024
Application Filed
Feb 27, 2025
Response after Non-Final Action
Feb 21, 2026
Non-Final Rejection — §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

1-2
Expected OA Rounds
82%
Grant Probability
87%
With Interview (+5.0%)
2y 5m
Median Time to Grant
Low
PTA Risk
Based on 900 resolved cases by this examiner. Grant probability derived from career allow rate.

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