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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 12/20/2024 and 10/2/2025 were filed in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
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.
1: Claim(s) 1-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Silicon Metalens Fabrication from Electron Beam to UV-Nanoimprint Lithography Baracu et al in view of CN 105278010 A Tian et al.
2: As for Claim 1, Baracu et al teaches A method to manufacture a meta-lens, comprising: depositing polysilicon on a substrate (see abstract on Page 1); coating the polysilicon with a photoresist (Page 2 teaches a negative or positive resist used in the manufacturing process); developing the photoresist with a mask pattern corresponding to a target array of pillar diameters of a meta-lens (Third paragraph on Page 2); and etching the polysilicon according to the developed photoresist mask pattern to generate polysilicon pillars extending from the substrate with a target height (pillars are depicted in Figure 5), wherein a height of each pillar is less than approximately three times a width or radius of each pillar (see figure 1 on Page 4) . However, does not teach annealing the deposited polysilicon on the substrate to reduce absorptive losses and improve transmission efficiency of optical radiation within a target operational frequency band.
Tian et al teaches on Pages 6 and 8 and in Claim 1 a method for manufacturing microlenses with polysilicon and teaches it is advantageous when forming lenses with polysilicon to perform a high temperature annealing process to eliminate lattice defects and internal stress which will in turn reduce absorptive losses and improve transmission efficiency of optical radiation within a target operational frequency band.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to perform a high temperature annealing process to eliminate lattice defects and internal stress as taught by Tian et al in the metalens manufacturing process of Baracu et al in order to eliminate lattice defects and internal stress which will in turn reduce absorptive losses and improve transmission efficiency of optical radiation within a target operational frequency band.
3: As for Claim 2, Baracu et al further teaches on Page 4 in the description of Figure 2, wherein the substrate comprises fused silica (fused silica wafer).
4: As for Claim 3, Baracu et al teaches forming metalenses by depositing polysilicon on a substrate and teaches on Page 6, third paragraph using a chemical vapor deposition process (e-beam evaporation method). However, does not explicitly teach using a low-pressure chemical vapor deposition (LPCVD) process.
Tian et al teaches on Pages 4 and 6 and a method for manufacturing microlenses with polysilicon and teaches it is advantageous when forming lenses with polysilicon to use a LPCVD mask layer to improve the formation of the lenses.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a low-pressure chemical vapor deposition (LPCVD) process as taught by Tian et al to form the metalenses of Baracu et al in order to improve the manufacturing process.
5: As for Claim 4, Baracu et al further teaches on Page 2, Lines 1-6 wherein the photoresist comprises a negative photoresist, and wherein developing the photoresist comprises an electron-beam lithography (EBL) process and a hard bake process.
6: As for Claim 5, Tian et al further teaches on Page 6 in step 7 wherein annealing the deposited polysilicon on the substrate to reduce absorptive losses and improve transmission efficiency comprises annealing at a temperature between 900 and 1100 degrees Celsius for a time period between 30 and 90 minutes (the examiner asserts that a 3-5 hour time period as taught by Tian et al includes both a 30 minute time period and a 90 minute time period).
7: As for Claim 6, Baracu et al further teaches on Page 5 in the description of Figure 3, and depicts in Figure 3 wherein the photoresist mask pattern corresponds to a rectangular array of pillars, such that the manufactured metalens has a rectangular shape (see Figures 1 and 3).
8: As for Claim 7, Baracu et al teaches A method to manufacture a meta-lens, comprising: depositing polysilicon on a substrate (see abstract on Page 1); coating the polysilicon with a photoresist (Page 2 teaches a negative or positive resist used in the manufacturing process); developing the photoresist with a mask pattern corresponding to a target array of pillar diameters of a meta-lens (Third paragraph on Page 2); and etching the polysilicon according to the developed photoresist mask pattern to generate polysilicon pillars extending from the substrate with a target height (pillars are depicted in Figure 5), wherein a height of each pillar is less than approximately three times a width or radius of each pillar (see figure 1 on Page 4) . However, does not teach annealing the deposited polysilicon on the substrate to reduce absorptive losses and improve transmission efficiency of optical radiation within a target operational frequency band.
Tian et al teaches on Pages 6 and 8 and in Claim 1 a method for manufacturing microlenses with polysilicon and teaches it is advantageous when forming lenses with polysilicon to perform a high temperature annealing process to eliminate lattice defects and internal stress which will in turn reduce absorptive losses and improve transmission efficiency of optical radiation within a target operational frequency band.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to perform a high temperature annealing process to eliminate lattice defects and internal stress as taught by Tian et al in the metalens manufacturing process of Baracu et al in order to eliminate lattice defects and internal stress which will in turn reduce absorptive losses and improve transmission efficiency of optical radiation within a target operational frequency band.
Furthermore, Baracu et al teaches a first plurality of passive deflector elements (metalens pillars) with varying diameters to direct a subset of wavelengths within a first bandwidth at a first deflection angle (Figure 11 and Page 14 teaches forming meta lenses with different configurations to operate in different wavelength ranges); and a second plurality of passive deflector elements with varying diameters to direct a subset of wavelengths within a second bandwidth at a second deflection angle. As depicted in Figure 11 multiple different metalens patterns can be formed based on different wavelength response characteristic that are desired.
9: As for Claim 8, Baracu et al further depicts in Figures 9 and 11 and teaches on Pages 12 and 13 wherein the first plurality of passive deflector elements (metalenses) comprises a first plurality of polysilicon pillars extending from the substrate, and wherein the second plurality of passive deflector elements comprises a second plurality of polysilicon pillars extending from the substrate. Multiple pillars with different dimension are formed on the substrate as depicted in Figure 9).
10: As for Claim 9, Baracu et al further teaches in Figure 1 and on Page 4 wherein a height of each pillar is less than approximately three times a diameter of each pillar (see Figure 1).
11: As for Claim 10, Baracu et al further teaches in Figure 11 and on Page 14 wherein each of the first and second bandwidths is at least 100 nanometers wide, and wherein the first bandwidth and the second bandwidth do not overlap. Baracu et al teaches multiple metalens configurations that result in different bandwidth configurations.
Allowable Subject Matter
Claims 11-14 are allowed.
The following is a statement of reasons for the indication of allowable subject matter: The prior art does not teach developing the photoresist with a mask pattern corresponding to a target array of passive deflector elements of a metalens filter; and etching the polysilicon according to the developed photoresist mask pattern to generate the metalens filer with a plurality of subwavelength deflector elements that extend from a substrate with a repeating periodic pattern of a spatially multiplexed set of frequency-specific deflector elements that have different diameters and constant interelement on-center spacings, the diameters and interelement on-center spacings of the spatially multiplexed set of frequency-specific detector elements selected to: direct optical radiation in a first band of optical radiation at a first deflection angle, and direct optical radiation in a second band of optical radiation at a second deflection angle, and wherein each subwavelength deflector element has a height and a width that are each less than a smallest wavelength in the first and second bands of optical radiation when taken in combination with all the limitations of the independent claim.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAMES M HANNETT whose telephone number is (571)272-7309. The examiner can normally be reached 8:00 AM-5:00 PM Monday thru Thursday.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Twyler Haskins can be reached at 571-272-7406 The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JAMES M HANNETT/Primary Examiner, Art Unit 2639
JMH
April 15, 2026
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