Prosecution Insights
Last updated: April 19, 2026
Application No. 18/487,750

MIXED-REALITY WAVEGUIDE COMBINER WITH GRADIENT REFRACTIVE INDEX GRATINGS

Non-Final OA §103§112
Filed
Oct 16, 2023
Examiner
KING, GEORGE G
Art Unit
2872
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Microsoft Technology Licensing, LLC
OA Round
1 (Non-Final)
58%
Grant Probability
Moderate
1-2
OA Rounds
2y 11m
To Grant
97%
With Interview

Examiner Intelligence

Grants 58% of resolved cases
58%
Career Allow Rate
338 granted / 579 resolved
-9.6% vs TC avg
Strong +38% interview lift
Without
With
+38.2%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
50 currently pending
Career history
629
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
40.3%
+0.3% vs TC avg
§102
23.9%
-16.1% vs TC avg
§112
29.5%
-10.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 579 resolved cases

Office Action

§103 §112
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 . Election/Restrictions Applicant’s election without traverse of Group I, Species A & 1, claims 1-11 in the reply filed on November 26, 2025 is acknowledged. Accordingly, claims 12-20 are withdrawn and claims 1-11 are examined below. Information Disclosure Statement The information disclosure statement (IDS) submitted on March 26, 2025 complies with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. Drawings The extensive drawings have not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant's cooperation is requested in correcting any errors of which applicant may become aware in the drawings. Specification The lengthy specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. Claims 8-11 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. Regarding claim 8 “the third region” has antecedent issues. It is unclear if the claim should depend from claim 3, which introduces a third region (assumed) or id a new/different element is being introduced. For purposes of examination the examiner will interpret the claim as depending from claim 3. Claims 9-11 are rejected under 35 U.S.C. 112(b) as being indefinite, since they depend on claim 8 and therefore have the same deficiencies. Regarding claim 9 “the two or more inkjet resin films are layered” raises clarity issues. It is unclear if applicant is claiming a manufacturing step or if applicant is claiming a final device structure. Applicant has withdrawn Species 2, drawn to two layers of different indices along the grating height (in favor of Species 1 with a greyscale index change along the grating height). In the election of November 26, 2025 applicant has indicated that claims 1-11, including 9, read on Group I, Species A and Species 1. Thus, the examiner concludes that it is a manufacturing step1. The following is a quotation of 35 U.S.C. 112(d): (d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers. Claim 7 is rejected under 35 U.S.C. 112(d) as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Regarding claim 7 (dependent of 1) the sole limitation “in which gratings in the SRG are slanted” fails to further limit the invention. Claim 1 already requires “the SRG including slanted gratings”. Applicant may cancel the claim, amend the claim to place the claim in proper dependent form, rewrite the claim in independent form, or present a sufficient showing that the dependent claim complies with the statutory requirements. 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 1-11 are rejected under 35 U.S.C. 103 as being unpatentable over Melli et al. US Patent Application Publication 2018/0095201 in view of Calafiore et al. US Patent 10,895,671. Regarding claims 1 and 7 Melli disclose an out-coupling diffractive optical element (DOE) (e.g. figures 2(IV) & 6 non-uniform diffraction grating 200 exit & pupil expansion/EPE diffractive element 608) in a waveguide combiner in a mixed-reality display system, employable by a user, that combines virtual images and views of a real world (no patentable weight2, further optical system 600 using non-uniform diffraction gratings paragraph [0064] “600 can be used for virtual and augmented reality applications”), comprising: a see-through optical substrate (e.g. substrate 610) having a first refractive index (inherent material property), the optical substrate propagating virtual images in total internal reflection along a propagation direction (paragraph [0066] “input light beams travels in the waveguide by total internal reflection … OPE diffractive element 606 on a layer is configured to deflect some of the input light beams to the EPE diffractive element 608”); and a surface relief grating (SRG) disposed on the optical substrate (e.g. 608), the SRG including gratings having a depth that increases along the propagation direction of the virtual images (e.g. figure 2 shows non-uniform grating that has increasing depth, which increases diffraction efficiency, and paragraph [0068] “second non-uniform grating can have a gradually increasing diffraction efficiency along the second direction”), the SRG configured for out-coupling the virtual images to an eye of the user (paragraph [0066] “608 that is configured to in turn deflect some of the deflected light beams out of the substrate 610, e.g., toward a user's eye”), wherein the SRG comprises gratings in at least two distinct regions, a first region (e.g. figure 2 right side with high ion density 204) including gratings with a first refractive index (inherent material property) that is lower relative to the refractive index of the optical substrate (inherent as explained below), and a second region including gratings (e.g. figure 2 left side with low ion density 204) with a second refractive index (inherent material property) that is higher relative to the refractive index of gratings in the first region (inherent as explained below), and wherein the regions are based on the grating depth in which grating depth is shallower for gratings in the first region relative to gratings in the second region (see figure 2(IV) showing left side with low ). Melli does not disclose the grating are slanted, as required by claims 1 and 7. Melli does not state the (inherent) physical properties that the first refractive index is lower relative to the refractive index of the optical substrate (n1<nsub), the second refractive index that is higher relative to the refractive index of gratings in the first region (n1<n2). Calafiore teaches a similar out-coupling DOE (title e.g. figures 24 & 27) with an intended use of combiner in a mixed-reality display system, employable by a user, that combines virtual images and views of a real world (abstract “used in a virtual-reality system or augmented-reality system” see figures 2-3) including an SRG (see figures 24 & 27) with a progressive change in ion implantation (e.g. see figures 22 & 26); and further teaches a slanted for the purpose of directing the output light without using a lens (column 7 line 57-column 8 line 11). Therefore, it would be obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for the gratings in the out-coupling DOE as disclosed by Melli to have a slant as taught by Calafiore for the purpose of directing the output light without using a lens. Regarding the examiner’s statement that the physical properties n1<nsub and n1<n2 are inherent – Calafiore teaches that the high ion implantation region has a lower refractive index than the low ion implantation region, see inter alia column 13 lines 34-43 “a variable refractive index after ion implantation. By selectively applying the ion implantation, the layer 2304 having the variable refractive index is formed on the substrate 815. In the embodiment shown in FIG. 23, n1=1.46 and n2=1.98”, see annotated figure A below. Melli’s substrate (with nsub) and leftmost grating (i.e. second region with n2) are un-implanted material 202 and the rightmost grating (i.e. fist region with n1) has high ion density material 204. As evidenced by Calafiore no/low ion density material have a refractive indices (i.e. n1 and nsub) greater than high ion density material (i.e. n2). It has been held “the discovery of a previously unappreciated property of a prior art composition, or of a scientific explanation for the prior art’s functioning, does not render the old composition patentably new to the discoverer." Atlas Powder Co. v. IRECO Inc., 190 F.3d 1342, 1347, 51 USPQ2d 1943, 1947 (Fed. Cir. 1999), see MPEP 2112. [AltContent: textbox (3rd region with graded implanted ion density )] [AltContent: textbox (1st region with high implanted ion density )][AltContent: textbox (substrate & 2nd region with no/low implanted ion density )] PNG media_image1.png 174 670 media_image1.png Greyscale [AltContent: textbox (graded high to low implanted ion density )] [AltContent: textbox (1st region )][AltContent: textbox (2nd region )][AltContent: textbox (graded high to low refractive index )] PNG media_image2.png 102 241 media_image2.png Greyscale Figure A. Annotated portion of Melli figure 2 (on left) showing graded implanted ion density and annotated portion of Calafiore figure 24 (on right) showing the inverse relationship between graded implanted ion density and graded refractive index. Regarding claim 2 the combination of Melli as modified by Calafiore discloses the out-coupling DOE of claim 1, as set forth above. Melli further discloses the SRG in the out-coupling DOE (e.g. 608) is further configured to expand an exit pupil of the virtual images (inter alia paragraph [0065] “exit pupil expansion (EPE) diffractive element 608”). Regarding claim 3 the combination of Melli as modified by Calafiore discloses the out-coupling DOE of claim 1, as set forth above. Melli further discloses it is further comprising a third region that is spatially disposed between the first region and the second region (e.g. middle gratings in figure 2(IV)), in which the third region comprises gratings with a third refractive index that is between the first and second refractive indexes (inherent since the ion implantation is graded, see paragraph [0030] & figure 2, resulting in a graded index using the reasoning set forth above). Regarding claim 4 the combination of Melli as modified by Calafiore discloses the out-coupling DOE of claim 3, as set forth above. Melli further discloses the refractive index of gratings in the third region (e.g. middle gratings in figure 2(IV)) is variable based on spatial location of gratings within the third region (inherent since the ion implantation is graded, see paragraph [0030] & figure 2, resulting in a graded index using the reasoning set forth above). Regarding claim 5 the combination of Melli as modified by Calafiore discloses the out-coupling DOE of claim 1, as set forth above. Melli further discloses the first refractive index of the gratings in the first region is continuously variable between a lowest value for gratings in the first region having farthest spatial separation from the second region and a highest value for gratings in the first region having closest spatial separation from the second region (inherent since the ion implantation is graded, see paragraph [0030] & figure 2, resulting in a graded index using the reasoning set forth above). Regarding claim 6 the combination of Melli as modified by Calafiore discloses the out-coupling DOE of claim 1, as set forth above. Melli further discloses the second refractive index of the gratings in the second region is continuously variable between a lowest value for gratings in the second region having closest spatial separation from the first region and a highest value for gratings in the second region having farthest spatial separation from the first region (inherent since the ion implantation is graded, see paragraph [0030] & figure 2, resulting in a graded index using the reasoning set forth above). Regarding claim 8-11 the combination of Melli as modified by Calafiore discloses the out-coupling DOE of claim 3, as set forth above. Melli does not disclose the gratings in the third region comprise two or more inkjet resin films having different refractive indexes, as recited in claim 8; or the two or more inkjet resin films are layered, as recited in claim 9; or the two or more inkjet resin films are configured in a one-dimensional or two-dimensional patterned array, as recited in claim 10; or the two or more inkjet resin films are at least partially merged, as recited in claim 11. Calafiore further teaches (see column 3 lines 25-35 figures 8-10) a grating being formed from two resins (e.g. first material 808 & second material 908) with different refractive indices (column 8 line 67-column 9 line 1 “808 has a first refractive index, n1” & column 9 lines 17-19 “second material has a second refractive index, n2 … n2 is greater than the first refractive index n1”) arrayed on a substrate (see figure 9 & column 9 line 55 “pattern of drops varies in two dimensions”) and can be layered (column 9 lines 51-54 “In some embodiments, drops of the first material 808 are placed on drops of the first material 808 and/or drops of the second material 908 are placed on drops of the second material 908”) merged (see figure 10 & column 9 lines 55-57 “Drops of material are configured to blend so that refractive index changes smoothly”) for the purpose of creating a grating with a refractive index that varies in one or two dimensions for use in a virtual-reality system or augmented-reality system to provide angular selectivity from display to a user's eye (column 3 lines 34-38). Therefore, it would be obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for the gratings in the out-coupling DOE as disclosed by the combination of Melli as modified by Calafiore to have the gratings in the third region comprise two or more inkjet resin films having different refractive indexes, and the two or more inkjet resin films are layered, and the two or more inkjet resin films are configured in a one-dimensional or two-dimensional patterned array, and the two or more inkjet resin films are at least partially merged as further taught by Calafiore for the purpose of creating a grating with a refractive index that varies in one or two dimensions for use in a virtual-reality system or augmented-reality system to provide angular selectivity from display to a user's eye. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Lee et al. US Patent Application Publication 2021/0199971; in regards to a similar slanted out-coupling DOE, e.g. see figure 19K. Luo et al. US Patent Application Publication 2022/0152724; in regards to a similar slanted out-coupling DOE, e.g. see figure 4. Calafiore et al. US Patent 10,823,887; in regards to a similar out-coupling DOE composed of resins, e.g. see figures 8-10. Any inquiry concerning this communication or earlier communications from the examiner should be directed to George G King whose telephone number is (303)297-4273. The examiner can normally be reached 9-5. 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. /George G. King/Primary Examiner, Art Unit 2872 December 16, 2025 1 It is noted that it has been held that the presence of process limitations (i.e. manufacturing step) in a product claim, which product does not otherwise patentably distinguish over the prior art, cannot impart patentability to the product. In re Stephens 135 USPQ 656 (CCPA 1965). Furthermore, the patentability of a product does not depend upon its method of production. If the product in a product by process claim is the same as or obvious from a product of the prior art, then the claim is unpatentable even though the prior art product was made by a different process. In re Thorpe, 227 USPQ 964, 966 (Fed Cir 1985). See MPEP 2113. 2 This recitation in the preamble is directed to intended use of the device and has not been given any patentable weight since it has been held "where a patentee defines a structurally complete invention in the claim body and uses the preamble only to state a purpose or intended use for the invention, the preamble is not a claim limitation" Kropa v. Robie, 187 F.2d at 152, 88 USPQ2d at 480-81, see MPEP 2111.02
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Prosecution Timeline

Oct 16, 2023
Application Filed
Dec 16, 2025
Non-Final Rejection — §103, §112
Mar 26, 2026
Examiner Interview Summary
Mar 26, 2026
Applicant Interview (Telephonic)

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Prosecution Projections

1-2
Expected OA Rounds
58%
Grant Probability
97%
With Interview (+38.2%)
2y 11m
Median Time to Grant
Low
PTA Risk
Based on 579 resolved cases by this examiner. Grant probability derived from career allow rate.

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