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 .
DETAILED ACTION
The instant application having Application No. 17/955,185 filed on September 28, 2022 is presented for examination by the examiner.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on March 19, 2026 has been entered.
The amended claims submitted March 19, 2026 in response to the office action mailed November 19, 2025 are under consideration. Claims 1-6, 8 and 10-22 are amended and pending.
Examiner Notes
Examiner cites particular columns and line numbers in the references as applied to the claims below for the convenience of the applicant. Although the specified citations are representative of the teachings in the art and are applied to the specific limitations within the individual claim, other passages and figures may apply as well. It is respectfully requested that, in preparing responses, the applicant fully consider the references in entirety as potentially teaching all or part of the claimed invention, as well as the context of the passage as taught by the prior art or disclosed by the examiner.
Claim Objections
The objections to the claims of the previous office action have been overcome by the amendments to the claims.
Claim Rejections - 35 USC § 112
The 35 USC §112 rejections of the previous office action have been overcome by the amendments to the claims. However, the following 35 USC §112 rejections are raised by the amendments.
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-6, 8 and 10-22 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Regarding claims 1-3, 10, 14 and 21 the limitation newly added to claims 1, 10 and 14 “wherein the gap is bounded by sidewalls of the plurality of device structures, sidewalls of the outer impedance matching layer, a top surface of the substrate, and the encapsulating layer” (emphasis added) fails to comply with the written description requirement. The specification as filed never uses the term “bound” or “bounding” or “bounded” and only discusses the encapsulating layer, optical cap or a capping layer very briefly. The examiner could only identify three such passages in paragraphs [0025], [0031] and [0034]:
[0025]: “The medium 115 may be a fluid, such as air or water, or an optical layer, such as an encapsulating layer or another optical device.”
[0031]: “In other embodiments, the medium 315 opposite the device layer 304 is an optical material, such as an optical cap or encapsulating layer.”
[0034]: “In embodiments described herein, the medium 315 may be any one of another optical layer, an optical device, or a fluid medium which the device structures 318 are immersed. Potential optical layers include a capping layer.”
None of these passages explain to what extent the encapsulating layer, optical cap or capping layer might or might not extend into the gaps, nor do these passages make any reference to Fig. 5F.
Furthermore, “encapsulating” would normally imply a conformal planarization layer that would both fill the gaps and create a flat surface on top of the device structures. Similarly, there is nothing about a capping layer that would preclude it from extending into the gaps.
Thus, the specification as filed, cannot support an interpretation of claims 1, 10 or 14 where “bounded by” takes its ordinary meaning that the upward extent of the gap is surrounded by the outer impedance matching layer and is bounded by a physical lower surface of an encapsulating layer.
This written description issue is worsened by the amendment to claim 2 which now recites “a medium disposed around the tip of each of the device structures, the medium comprising the encapsulating layer” (emphasis added) where “around the tip” would imply that the encapsulating layer does extend into the spaces between the device structures. If this were the case, there would be no way of knowing whether the gap was actually still bounded by the side surfaces of the outer impedance matching layer. This creates a written description issue for claim 2, and muddies the waters even further for claim 1.
Claim 3, which depends from claims 1 and 2, and claim 21 that depends from claim 1 now also appear to require the presence of air in the gaps underneath the encapsulating layer. Such a combination of mediums 315 or 115 being both air and an encapsulating layer is never discussed in the body of the specification. Nor does the specification as filed discuss what might or might not be within the gaps underneath an encapsulating layer. An ordinary skilled artisan cannot assume that the encapsulation layer does not extend into the full depth of the gaps, and thus deduce the presence of another medium, such as air, therein. Thus the limitations of claims 3 and 21 lack written description support.
Claims 2-6, 8 and 21-22 depend from claim 1 and inherit and do not mitigate the above written description issue from claim 1.
Claims 11-13 depend from claim 10 and inherit and do not mitigate the above written description issue from claim 10.
Claims 15-20 depend from claim 14 and inherit and do not mitigate the above written description issue from claim 14.
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-6, 8 and 10-22 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claims 1, 10 and 14, the newly added limitation “wherein the gap is bounded by sidewalls of the plurality of device structures, sidewalls of the outer impedance matching layer, a top surface of the substrate, and the encapsulating layer” (emphasis added) is indefinite for at least the following reasons. The specification as filed never uses the term “bound” or “bounding” or “bounded” and only discusses the encapsulating layer, optical cap or a capping layer very briefly. The examiner could only identify three such passages in paragraphs [0025], [0031] and [0034]:
[0025]: “The medium 115 may be a fluid, such as air or water, or an optical layer, such as an encapsulating layer or another optical device.”
[0031]: “In other embodiments, the medium 315 opposite the device layer 304 is an optical material, such as an optical cap or encapsulating layer.”
[0034]: “In embodiments described herein, the medium 315 may be any one of another optical layer, an optical device, or a fluid medium which the device structures 318 are immersed. Potential optical layers include a capping layer.”
None of these passages explain to what extent the encapsulating layer, optical cap or capping layer might or might not extend into the gaps. Furthermore, “encapsulating” would normally imply a conformal planarization layer that would both fill the gaps and create a flat surface on top of the device structures. Similarly, there is nothing about a capping layer that would preclude it from extending into the gaps. Additionally, “bounded by” must also be understood in the context of claim 2 which now recites “a medium disposed around the tip of each of the device structures, the medium comprising the encapsulating layer” (emphasis added) where “around the tip” would imply that the encapsulating layer does extend into the spaces between the device structures. Claim 3, which depends from claims 1 and 2, now also appears to require the presence of air in the gaps underneath the encapsulating layer, where such a combination of 315 or 115 being both air and an encapsulating layer is never discussed in the body of the specification.
The problem that all of these scant descriptions raise in terms of indefiniteness is that, typically, one would expect bounded by to be the situation depicted in Fig. 5F by the dashed line along a “bottom” of medium 315, where the encapsulating layer ends and the gap begins. However, none of paragraphs [0025], [0031] or [0034] are specifically discussing Fig. 5F or any such bottom surface. Thus the dashed line could just as well be an imaginary boundary line “defining” the top of the gap, not any physical surface. Furthermore, given claim 2, if the encapsulating layer extends into the space between the device structures, there is no way of knowing whether or not the outer impedance matching layer will still be a boundary of the gap, since we don’t know how far into the spaces the encapsulating layer extends. Thus one is left with only one fully supported meaning for the above limitation specifically: “wherein the gap is bounded by sidewalls of the plurality of device structures, sidewalls of the outer impedance matching layer, a top surface of the substrate, and an imaginary plane defined by the top surface of the outer impedance matching layer wherein the encapsulating layer encloses the gap”. Such an interpretation would encompass both a capping layer that rests on top of the outer impedance matching layer and does not protrude into the gaps, as well as an encapsulating layer that extends between the outer impedance matching layer and/or the device structures. However, it would be highly improper to narrowly construe this new limitation as limited to a meaning that required this degree of guess-work to assemble.
Appropriate correction is required. The only remedy that occurs to the examiner is to simply omit this recitation, because any re-wording of it that would be supported by the application as filed would be duplicative to that which is already stated in the claims.
Claims 2-6, 8 and 21-22 depend from claim 1 and inherit and do not mitigate the above indefiniteness issue from claim 1.
Claims 11-13 depend from claim 10 and inherit and do not mitigate the above indefiniteness issue from claim 10.
Claims 15-20 depend from claim 14 and inherit and do not mitigate the above indefiniteness issue from claim 14.
Regarding claim 2, the limitation “a medium disposed around the tip of each of the device structures, the medium comprising the encapsulating layer” is indefinite because it is unclear whether or not “around the tip” requires the encapsulating layer to extend into the spaces between the device structures. As noted above for claim 1, no details of the encapsulating layer are provided in the specification as filed that would clarify this issue. Appropriate correction is required. If the examiner correctly understands the desired meaning, the examiner recommends the following amendment:
2. (proposed amendment) The optical device of claim 1, wherein outgoing radiation exits from a tip of each of the device structures and passes through a medium disposed above the tip of each of the device structures, the medium comprising the encapsulating layer.
Claim 3 depends from claim 2 and inherits and does not mitigate the above indefiniteness issue from claim 2.
Regarding claims 3 and 21, the limitation “wherein the gap is air” is indefinite for at least the following reasons. First, the specification as filed does not discuss what might or might not be within the gaps underneath an encapsulating layer. An ordinary skilled artisan cannot assume that the encapsulation layer does not extend into the full depth of the gaps, and thus deduce the presence of another medium, such as air, therein. Second, “the gap is air” is not the same statement as “the gap is filled with air”. One might think that this is a distinction without a difference, but words matter, especially in a situation where there is a lack of explicit support. Due to these two problems, it is unclear whether claims 3 and 21 are requiring that there is air present in the gap in the end product, or merely that when the gap was formed it was air, i.e. that the gap is air that has been filled by the encapsulating layer. In light of the 112(a) rejection above, cancelling claims 3 and 21 may be the only remedy. If the 112(a) rejection can be overcome in another manner, the examiner recommends amending claims 3 and 21 as follows:
3. (proposed amendment) The optical device of claim 2, wherein the gap is filled with air.
21. (proposed amendment) The optical device of claim 1, wherein the gap is filled with air.
Claim Rejections - 35 USC § 103
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.
Claims 1-2, 4-6, 10-13 and 21-22 are rejected under 35 U.S.C. 103 as being unpatentable over Greiner et al. US 2020/0271837 A1 (cited in an IDS, hereafter Greiner).
Regarding claim 1, Greiner teaches “An optical device (paragraph [0079]: “a first set of specific illustrative examples arranged as in FIG. 1F”), comprising:
a substrate (substrate 10) having a substrate refractive index (1.45 see paragraph [0079]: “the substrate 10 is fused silica (nS=1.45; about 0.35 mm thick),”);
a plurality of device structures (non-recessed areal regions 107) disposed over the substrate (see Fig. 1F), adjacent device structures of the plurality of device structures defining a gap therebetween (recessed areal regions 103, note that although in paragraph [0079] the regions 107 are circular posts arranged in a grid pattern, they still define gaps between each of the posts even if those gaps are interconnected), each device structure comprising:
a device layer (intermediate layer 20), the device layer including a device material (paragraph [0079] “the intermediate layer 20 is silicon nitride”) having a device refractive index of about 1.9 to about 3.5 (1.98 paragraph [0079]: “silicon nitride (nI=1.98; dI=1400 nm)”); and
an outer impedance matching layer (topmost layer 30, which is an impedance matching layer because it has a lower refractive index closer to that of air, than layer 20 does) having an impedance refractive index (1.45 paragraph [0079]: “the topmost layer 30 is silicon dioxide (SiO2; nT=1.45; dT=160 nm).”) and contacting the device layer (see Fig. 1F),
wherein the outer impedance refractive index is about 1.4 to about 1.8 (1.45 paragraph [0079]); and
… wherein the gap between adjacent device structures is bounded by sidewalls of the plurality of device structures, sidewalls of the outer impedance matching layer, a top surface of the substrate… (see Fig. 1F, the gap is bounded by the sidewalls of 107 including both layers 20 and 30. The gap is also bounded by substrate 10, even though bottom layer 40 is within the gap so defined).”
However, the embodiment of paragraph [0079] and Fig. 1F of Greiner fails to explicitly teach “an encapsulating layer contacting a top surface of the outer impedance matching layer, wherein the gap between adjacent device structures is bounded by… the encapsulating layer.”
However, paragraph [0044] of Greiner teaches “an encapsulating layer (paragraph [0044]: “solid fill medium 70”) contacting a top surface of the outer impedance matching layer (paragraph [0044]: “the non-recessed areal regions 107 are covered by, the fill medium 70.”), wherein the gap between adjacent device structures is bounded by… the encapsulating layer (paragraph [0044]: “the recessed areal regions 103 are filled with, and the non-recessed areal regions 107 are covered by, the fill medium 70.” Thus the solid fill medium 70 is present and covers the upper-most end of the gaps, thereby bounding the gaps. The presence of the fill medium protruding into the gaps is not precluded by the claim for at least two reasons (1) “encapsulating” would normally be construed as both conformally filling and covering the underlying structures (2) no other medium is explicitly recited as residing in the gaps and (3) in light of the complicating 112(a) and 112(b) issues explained above, a narrow, literal, interpretation of “bounded by” is unsupportable.).”
Alternatively, Figs. 3A-3F of Greiner teach “an encapsulating layer (a reflector 50) contacting a top surface of the outer impedance matching layer (see Figs. 3A-3F and paragraph [0067]: “the reflector 50 can be formed on a separate reflector substrate (not shown) and then positioned against the topmost layer 30 of the non-recessed areal regions 107, covering both the recessed and non-recessed areal regions 103 and 107.”), wherein the gap between adjacent device structures is bounded by… the encapsulating layer (see Figs. 3A-3F and paragraph [0067]: “Retention of the reflector 50 against the non-recessed areal regions 107 can enable use of vacuum, gas, or liquid as the fill medium 70. In those examples the optical element can be immersed in the fill medium while the reflector 50 is secured in place.”).”
Greiner further teaches (paragraph [0066]): “The optical element is structurally arranged so as to receive on at least a portion of the contiguous multitude of areal regions 103 and 107 the incident optical signal 99 propagating through the substrate 10, and to reflect the phase-transformed optical signal 97 to propagate through the substrate 10. The effective phase transformation φeff(x,y) is effected by double-pass transmission through the phase-transforming layer 100 with an intervening reflection by the reflector 50.”
(paragraph [0067]): “In some examples, the reflector 50 can be formed (e.g., grown or deposited) on the topmost layer 30 of the non-recessed areal regions 107 and on a solid fill medium 70 filling the recessed areal regions 103. Such examples typically would require a solid fill medium 70 and some sort of planarization process, after forming the areal regions 103 and 107 and filling with the fill medium 70, before forming the reflector 50… In some examples the fill medium 70 can act as an adhesive, typically in the form a liquid or semiliquid precursor that is then cured to form a solid fill medium and adhesive.”
(paragraph [0088]): “Unless specific arrangements described herein are mutually exclusive with one another, the various implementations described herein can be combined in whole or in part to enhance system functionality or to produce complementary functions.”
Thus it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the specific example of paragraph [0079] having particular choices for the refractive indices as claimed, with an embodiment where a solid fill medium 70 is provided because Greiner teaches that (paragraph [0088]): “Unless specific arrangements described herein are mutually exclusive with one another, the various implementations described herein can be combined in whole or in part to enhance system functionality or to produce complementary functions.” Furthermore, one of ordinary skill in the art would have been motivated to make such a combination in order to protect the optical device structures with a solid encapsulant or to provide a planar surface on which a reflector could be formed or an adhesive by which a reflector could be attaches (paragraph [0067]).
Alternatively, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the specific example of paragraph [0079] having particular choices for the refractive indices as claimed, with a reflector that encapsulates the recessed and non-recessed areas and bound the gaps therebetween as taught by Figs. 3A-3F of Greiner for the purpose of to reflecting the phase-transformed optical signal 97 to propagate through the substrate 10, such that the effective phase transformation φeff(x,y) is effected by double-pass transmission through the phase-transforming layer 100 with an intervening reflection by the reflector 50 as taught by Greiner (paragraph [0066]).
Regarding claim 2, the Greiner combination of paragraph [0097] with the solid fill medium of paragraph [0044] introduced for claim 1 further teaches “The optical device of claim 1, wherein outgoing radiation (paragraph [0024]: “[0024] The optical element is structurally arranged so as to receive on at least a portion of the contiguous multitude of areal regions 103 and 107 an incident optical signal 99, within the operational wavelength range, and to transmit or reflect at least a portion of the incident optical signal 99 as a phase-transformed optical signal 97.”) exits from a tip of each of the device structures (see Fig. 1F where outgoing optical signal 97 exits from the tips of 107) and passes through a medium disposed around the tip of each device structure (medium 70), the medium comprising the encapsulating layer (see claim 1, 70 can be a solid fill medium as discussed in at least paragraph [0044]).”
Regarding claim 4, the Greiner combination teaches “The optical device of claim 1,” and Greiner paragraph [0079] further teaches “wherein the impedance refractive index falls in a range produced by a second formula, wherein the second formula is:
PNG
media_image1.png
34
406
media_image1.png
Greyscale
wherein nair is a refractive index of air (1.0 or 1.0003), ndevice is the device refractive index (paragraph [0079] silicon nitride n=1.98), and nouter.impedance is the refractive index of impedance matching layer (paragraph [0079] silicon dioxide n=1.45, Thus,
PNG
media_image2.png
28
132
media_image2.png
Greyscale
=
1.98
×
0.75
=
1
.
055
and
PNG
media_image3.png
26
126
media_image3.png
Greyscale
=
1.98
×
1.25
=
1.759
where 1.45 is within the claimed range.).”
Regarding claim 5, the Greiner combination teaches “The optical device of claim 1,” and Greiner paragraph [0079] further teaches “wherein each device structure further comprises an inner impedance matching layer (bottom layer 40 which is an inner impedance matching layer in that it has a refractive index between that of the substrate and that of the intermediate layer see paragraph [0079]) disposed between the substrate and the device layer (see Fig. 1F), the inner impedance matching layer having an inner impedance refractive index of about 1.4 to about 2.5 (1.65 paragraph [0079]: “the bottom layer 40 is aluminum oxide (Al2O3; nB =1.65; dB=160 nm),”).”
Regarding claim 6, the Greiner combination teaches “The optical device of claim 1,” and Greiner paragraph [0079] further teaches “wherein the inner impedance refractive index falls in a range produced by a third formula, wherein the third formula is:
PNG
media_image4.png
20
392
media_image4.png
Greyscale
wherein nsubstrate is the substrate refractive index (paragraph [0079] fused silica n=1.45), ndevice is the device refractive index (paragraph [0079] silicon nitride n=1.98), and ninner.impedance is the inner impedance refractive index (paragraph [0079] aluminum oxide n=1.65, Thus,
PNG
media_image5.png
20
140
media_image5.png
Greyscale
=
1.45
×
1.98
×
0.75
=
1.27
and =
1.45
×
1.98
×
1.25
=
2.118
where 1.65 is within the claimed range).”
Regarding claim 10, Greiner teaches “An optical device (paragraph [0079]: “a first set of specific illustrative examples arranged as in FIG. 1F”), comprising:
a substrate (substrate 10);
a plurality of device structures (non-recessed areal regions 107) disposed over the substrate (see Fig. 1F), adjacent device structures of the plurality of device structures defining a gap therebetween (recessed areal regions 103, note that although in paragraph [0079] the regions 107 are circular posts arranged in a grid pattern, they still define gaps between each of the posts even if those gaps are interconnected), each device structure comprising:
an inner impedance matching layer (paragraph [0079] bottom layer 40, which is an inner impedance matching layer in that it has a refractive index between that of the substrate and that of the intermediate layer see paragraph [0079]) disposed on a top surface of the substrate (see Fig. 1F) and having an inner impedance refractive index (1.65 paragraph [0079]: “the bottom layer 40 is aluminum oxide (Al2O3; nB =1.65; dB=160 nm),”);
a device layer (intermediate layer 20) disposed on the inner impedance matching layer (see Fig. 1F) and having a device refractive index (1.98 paragraph [0079]: “silicon nitride (nI=1.98; dI=1400 nm)”); and
an outer impedance matching layer (topmost layer 30, which is an impedance matching layer because it has a lower refractive index closer to that of air, than layer 20 does) disposed on the device layer (see Fig. 1F) and having an outer impedance refractive index (1.45 paragraph [0079]: “the topmost layer 30 is silicon dioxide (SiO2; nT=1.45; dT=160 nm).”),
wherein the outer impedance refractive index is about 1.4 to about 1.8 (1.45 paragraph [0079]); and
wherein the inner impedance refractive index (1.65 paragraph [0079]: “the bottom layer 40 is aluminum oxide (Al2O3; nB =1.65; dB=160 nm),”) is between (1.65 is between 1.45 and 1.98) a substrate refractive index (1.45 see paragraph [0079]: “the substrate 10 is fused silica (nS=1.45; about 0.35 mm thick),”) and the device refractive index (1.98 paragraph [0079]: “silicon nitride (nI=1.98; dI=1400 nm)”); and
… wherein the gap between adjacent device structures is bounded by sidewalls of the plurality of device structures, sidewalls of the outer impedance matching layer, a top surface of the substrate… (see Fig. 1F, the gap is bounded by the sidewalls of 107 including both layers 20 and 30. The gap is also bounded by substrate 10, even though bottom layer 40 is within the gap so defined).”
However, the embodiment of paragraph [0079] and Fig. 1F of Greiner fails to explicitly teach “an encapsulating layer contacting a top surface of the outer impedance matching layer, wherein the gap between adjacent device structures is bounded by… the encapsulating layer.”
However, paragraph [0044] of Greiner teaches “an encapsulating layer (paragraph [0044]: “solid fill medium 70”) contacting a top surface of the outer impedance matching layer (paragraph [0044]: “the non-recessed areal regions 107 are covered by, the fill medium 70.”), wherein the gap between adjacent device structures is bounded by… the encapsulating layer (paragraph [0044]: “the recessed areal regions 103 are filled with, and the non-recessed areal regions 107 are covered by, the fill medium 70.” Thus the solid fill medium 70 is present and covers the upper-most end of the gaps, thereby bounding the gaps. The presence of the fill medium protruding into the gaps is not precluded by the claim for at least two reasons (1) “encapsulating” would normally be construed as both conformally filling and covering the underlying structures (2) no other medium is explicitly recited as residing in the gaps and (3) in light of the complicating 112(a) and 112(b) issues explained above, a narrow, literal, interpretation of “bounded by” is unsupportable.).”
Alternatively, Figs. 3A-3F of Greiner teach “an encapsulating layer (a reflector 50) contacting a top surface of the outer impedance matching layer (see Figs. 3A-3F and paragraph [0067]: “the reflector 50 can be formed on a separate reflector substrate (not shown) and then positioned against the topmost layer 30 of the non-recessed areal regions 107, covering both the recessed and non-recessed areal regions 103 and 107.”), wherein the gap between adjacent device structures is bounded by… the encapsulating layer (see Figs. 3A-3F and paragraph [0067]: “Retention of the reflector 50 against the non-recessed areal regions 107 can enable use of vacuum, gas, or liquid as the fill medium 70. In those examples the optical element can be immersed in the fill medium while the reflector 50 is secured in place.”).”
Greiner further teaches (paragraph [0066]): “The optical element is structurally arranged so as to receive on at least a portion of the contiguous multitude of areal regions 103 and 107 the incident optical signal 99 propagating through the substrate 10, and to reflect the phase-transformed optical signal 97 to propagate through the substrate 10. The effective phase transformation φeff(x,y) is effected by double-pass transmission through the phase-transforming layer 100 with an intervening reflection by the reflector 50.”
(paragraph [0067]): “In some examples, the reflector 50 can be formed (e.g., grown or deposited) on the topmost layer 30 of the non-recessed areal regions 107 and on a solid fill medium 70 filling the recessed areal regions 103. Such examples typically would require a solid fill medium 70 and some sort of planarization process, after forming the areal regions 103 and 107 and filling with the fill medium 70, before forming the reflector 50… In some examples the fill medium 70 can act as an adhesive, typically in the form a liquid or semiliquid precursor that is then cured to form a solid fill medium and adhesive.”
(paragraph [0088]): “Unless specific arrangements described herein are mutually exclusive with one another, the various implementations described herein can be combined in whole or in part to enhance system functionality or to produce complementary functions.”
Thus it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the specific example of paragraph [0079] having particular choices for the refractive indices as claimed, with an embodiment where a solid fill medium 70 is provided because Greiner teaches that (paragraph [0088]): “Unless specific arrangements described herein are mutually exclusive with one another, the various implementations described herein can be combined in whole or in part to enhance system functionality or to produce complementary functions.” Furthermore, one of ordinary skill in the art would have been motivated to make such a combination in order to protect the optical device structures with a solid encapsulant or to provide a planar surface on which a reflector could be formed or an adhesive by which a reflector could be attaches (paragraph [0067]).
Alternatively, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the specific example of paragraph [0079] having particular choices for the refractive indices as claimed, with a reflector that encapsulates the recessed and non-recessed areas and bound the gaps therebetween as taught by Figs. 3A-3F of Greiner for the purpose of to reflecting the phase-transformed optical signal 97 to propagate through the substrate 10, such that the effective phase transformation φeff(x,y) is effected by double-pass transmission through the phase-transforming layer 100 with an intervening reflection by the reflector 50 as taught by Greiner (paragraph [0066]).
Regarding claim 11, the Greiner combination teaches “The optical device of claim 10” and Greiner further teaches “wherein the inner impedance refractive index is about 1.4 to about 2.5 (1.65 paragraph [0079]: “the bottom layer 40 is aluminum oxide (Al2O3; nB =1.65; dB=160 nm),”).”
Regarding claim 12, the Greiner combination teaches “The optical device of claim 10,” and Greiner paragraph [0079] further teaches “wherein the inner impedance refractive index falls in a range produced by a third formula, wherein the third formula is:
PNG
media_image4.png
20
392
media_image4.png
Greyscale
wherein nsubstrate is the substrate refractive index (paragraph [0079] fused silica n=1.45), ndevice is the device refractive index (paragraph [0079] silicon nitride n=1.98), and ninner.impedance is the inner impedance refractive index (paragraph [0079] aluminum oxide n=1.65, Thus,
PNG
media_image5.png
20
140
media_image5.png
Greyscale
=
1.45
×
1.98
×
0.75
=
1.27
and =
1.45
×
1.98
×
1.25
=
2.118
where 1.65 is within the claimed range).”
Regarding claim 13, the Greiner combination teaches “The optical device of claim 10,” and Greiner further teaches “wherein:
the device layer is one or a combination of germanium (Ge), silicon (Si), silicon nitride (Si3N4), titanium dioxide (TiO2), hafnium oxide (HfO2), tantalum pentoxide (Ta205), or scandium oxide (Sc203) (paragraph [0079]: “the intermediate layer 20 is silicon nitride”).”
Regarding claim 21, the Greiner combination of the specific example of paragraph [0079] and the embodiments of Figs. 3A-3F with an encapsulating reflector 50 introduced for claim 1 teaches “The optical device of claim 1, wherein the gap is air (paragraph [0067]: “Retention of the reflector 50 against the non-recessed areal regions 107 can enable use of vacuum, gas, or liquid as the fill medium 70” and paragraph [0075]: “Examples of suitable materials for the fill medium 70 include one or more of: vacuum; one or more of air, nitrogen, noble gas, or other inert gas;” emphasis added).”
Regarding claim 22, the Greiner combination teaches “The optical device of claim 1,” and Greiner further teaches “wherein the outer impedance refractive index (1.45 paragraph [0079]: “the topmost layer 30 is silicon dioxide (SiO2; nT=1.45; dT=160 nm).”) is between the substrate refractive index (1.45 see paragraph [0079]: “the substrate 10 is fused silica (nS=1.45; about 0.35 mm thick),”) and the device refractive index (1.98 paragraph [0079]: “silicon nitride (nI=1.98; dI=1400 nm)”).”
Note that 1.45 is consider to be “between” 1.45 and 1.98, because it is within normal English usage to include the endpoints of the range when interpreting “between”.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Greiner et al. US 2020/0271837 A1 (cited in an IDS, hereafter Greiner) as applied to claim 2 above, or in the alternative further in view of Mossberg et al. US 2009/0116790 A1 (hereafter Mossberg).
Regarding claim 3, the Greiner combination of paragraph [0097] with the solid fill medium of paragraph [0044] introduced for claim 1 further teaches “The optical device of claim 2, wherein the gap is air (paragraph [0044]: “After the recessed and non-recessed areal regions 103 and 107 are formed, the recessed areal regions 103 are filled with, and the non-recessed areal regions 107 are covered by, the fill medium 70.” Thus gaps that are air are formed prior to a medium which fills them, thus the gaps themselves are air.)”
In the alternative, where in light of 35 USC §112 issues above claim 3 is interpreted as requiring at least some of the gap is filled with air after the encapsulating layer is present, the Greiner combination of paragraph [0097] with the solid fill medium of paragraph [0044] would fail to meet “the gap is air”, but such a limitation would also have been obvious as follows.
Figs. 3A-3F teach a layer 50, paragraph [0066]: “positioned against the topmost layer 30 so as to cover the multitude of recessed and non-recessed areal regions 103 and 107.” Figs. 3A-3F further teach “the gap is air (paragraph [0067]: “Retention of … 50 against the non-recessed areal regions 107 can enable use of vacuum, gas, or liquid as the fill medium 70.” and paragraph [0075]: “Examples of suitable materials for the fill medium 70 include one or more of: vacuum; one or more of air, nitrogen, noble gas, or other inert gas;” emphasis added).”
Greiner further teaches (paragraph [0067]): “In other examples, the reflector 50 can be formed on a separate reflector substrate (not shown) and then positioned against the topmost layer 30 of the non-recessed areal regions 107, covering both the recessed and non-recessed areal regions 103 and 107. In such examples the reflector 50 can be o retained against the non-recessed areal regions in any suitable way, e.g., by one or more mechanical clamps or retainers, by optical contacting, by diffusion bonding, or by an adhesive.”
Mossberg teaches (claim 1) “A optical device (e.g. Figs. 5A-5B, which are metasurfaces because they meet all of the limitations below, have sizes below the operating wavelength including sub-micron dimensions, see Fig. 14 and paragraph [0071] “The grating period is 1.0638 µm and the duty cycle 56%, i.e., the grating line width is 596 nm and the trench width is 468 nm. The grating is optimized for operation as a demultiplexer in the ITU telecom C-band, 1526-1566 nm.”), comprising:
a substrate (substrate 502) having a substrate refractive index (paragraph [0068]: “The substrate 1200 comprises fused silica or similar material (n=1.446)”, paragraph [0070]: “All dimensions, materials, refractive indices and other optical properties in FIGS. 13A and 13B are the same as those of FIG. 12”, paragraph [0071]: “fused silica substrate 1400 (n=1.446)”);
a plurality of device structures (503) disposed over the substrate (see Figs. 5A-5B), adjacent device structures of the plurality of device structures defining a gap therebetween (see Figs. 5A-5B), each device structure comprising:
a device layer (503) the device layer including a device material (the material of 503) having a device refractive index of about 1.9 to about 3.5 (paragraph [0097] teaches “Any suitable material or combination of materials can be employed for forming a grating layer, impedance matching layer, reflective layer, or substrate that exhibits suitable transparency over the relevant operational wavelength range and suitable bulk refractive index. Suitable material can include, are not limited to, silicon, doped silicon, silicon nitride, silicon oxynitride, titanium dioxide… ambient atmosphere, air, or inert gas.” emphasis added. For example titanium dioxide has n=2.6); and…
an encapsulating layer (505)…
wherein the gap between adjacent device structures is bounded by the sidewalls of the plurality of device structures, the top surface of the substrate, and the encapsulating layer (see Fig. 5B).”
(claim 2) “wherein outgoing radiation exits from a tip of each of the device structures (see Fig. 1B) and passes through a medium (see Fig. 5B) disposed around the tip of each of the device structures (see Fig. 5B), the medium comprising the encapsulating layer (see Fig. 5B).
(claim 3) “wherein the gap is air (paragraph [0042]: “The second grating regions 102 can be empty space or can be filled with air” and paragraph [0057]: “a second impedance matching layer 505 is formed on a second substrate 504, which is then pressed onto the grating layer 503”).”
Mossberg further teaches (paragraph [0057]): “Third, a second impedance matching layer 505 is formed on a second substrate 504, which is then pressed onto the grating layer 503 and held in place by optical contacting. To further secure the layers, the edge of the optical grating can be coated or sealed with epoxy or other suitable adhesive.”
Thus it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to cover the recessed and non-recessed areas with one layer while retaining a fill medium of air in the gaps as taught by Greiner Figs. 3A-3F and Mossberg (Figs. 5A-5B) in the device of the Greiner combination, because Greiner teaches that the covering layer and the fill medium can be of different materials and because Mossberg teaches attaching a separate transparent layer to the tops of the device structures. One would have been motivated to choose to manufacture the optical device in that way so that a separately formed layer can be retained against the non-recessed areal regions in any suitable way, e.g., by one or more mechanical clamps or retainers, by optical contacting, by diffusion bonding, or by an adhesive as taught by Greiner (paragraph [0067]) and Mossberg (paragraph [0057]) which may facilitate simplifications and reductions in cost of manufacturing.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Greiner et al. US 2020/0271837 A1 (cited in an IDS, hereafter Greiner) as applied to claim 1 above, and further in view of Mossberg et al. US 2009/0116790 A1 (hereafter Mossberg).
Regarding claim 8, the Greiner combination teaches “The optical device of claim 1,” and Greiner further teaches “wherein … the outer impedance matching layer comprises silicon oxide or aluminum oxide (paragraph [0079]: “the topmost layer 30 is silicon dioxide (SiO2; nT=1.45; dT=160 nm).”).”
However, Greiner fails to teach “wherein the device layer comprises titanium dioxide”. Note however that Greiner teaches (paragraph [0035]): It should be appreciated that there can be many combinations of the parameters nT, dT, nI, dI, and nF that can result in the desired phase function φeff(x,y). Within that solution space, specific values of the parameters nT, dT, nI, dI, and nF can be selected based on any one or more necessary, desirable, or suitable criteria, including, e.g.: material cost, availability, or physico-chemical properties or compatibilities; or one or more improved performance parameters of the optical element.”
Mossberg teaches (claim 1) “A optical device (e.g. Figs. 12-14, which are metasurfaces because they meet all of the limitations below, have sizes below the operating wavelength including sub-micron dimensions, see Fig. 14 and paragraph [0071] “The grating period is 1.0638 µm and the duty cycle 56%, i.e., the grating line width is 596 nm and the trench width is 468 nm. The grating is optimized for operation as a demultiplexer in the ITU telecom C-band, 1526-1566 nm.”), comprising:
a substrate (substrate 1200, 1300, 1400) having a substrate refractive index (paragraph [0068]: “The substrate 1200 comprises fused silica or similar material (n=1.446)”, paragraph [0070]: “All dimensions, materials, refractive indices and other optical properties in FIGS. 13A and 13B are the same as those of FIG. 12”, paragraph [0071]: “fused silica substrate 1400 (n=1.446)”);
a plurality of device structures (1201,1202,1203 or 1301,1302,1303 or 1401,1402,1403) disposed over the substrate (see Figs. 12-14), adjacent device structures of the plurality of device structures defining a gap therebetween (see Figs. 12-14), each device structure comprising:
a device layer (1201, 1301 or 1401) the device layer including a device material (the material of 1201, 1301 or 1401) having a device refractive index of about 1.9 to about 3.5 (paragraph [0097] teaches “Any suitable material or combination of materials can be employed for forming a grating layer, impedance matching layer, reflective layer, or substrate that exhibits suitable transparency over the relevant operational wavelength range and suitable bulk refractive index. Suitable material can include, are not limited to, silicon, doped silicon, silicon nitride, silicon oxynitride, titanium dioxide… ambient atmosphere, air, or inert gas.” emphasis added. For example titanium dioxide has n=2.6); and
an outer impedance matching layer (1202, 1302, 1402 or 1403) having an impedance refractive index (paragraph [0068]: “impedance matching layer 1202 of thickness b=300 nm and refractive index 1.444.” paragraph [0070]: “All dimensions, materials, refractive indices and other optical properties in FIGS. 13A and 13B are the same as those of FIG. 12” or paragraph [0071]: “an upper impedance matching layer 1403 comprising silicon dioxide (n=1.45).”) and contacting the device layer (see Figs. 12-14), wherein, the impedance refractive index is about 1.4 to about 1.8 (1.444 and 1.45 are less than 2.2); and…
wherein the gap between adjacent device structures is bounded by sidewalls of the plurality of device structures, sidewalls of the outer impedance matching layer, a top surface of the substrate (see Figs. 12-14).”
(claim 8) “wherein the device layer comprises titanium oxide (paragraph [0068] teaches “As with previous embodiments, other specific material with corresponding refractive indices and thicknesses can be employed to provide essentially equivalent performance” and paragraph [0097] teaches “Any suitable material or combination of materials can be employed for forming a grating layer, … Suitable material can include, are not limited to … titanium dioxide”).”
It is a well-established proposition that the selection of a known material based on its suitability for its intended use is within the skill of one of ordinary skill in the art Sinclair & Carroll Co. v.Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945) See also In reLeshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960) (selection of a known plastic to make a container of a type made of plastics prior to the invention was held to be obvious). MPEP §2144.07.
Thus it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to choose titanium dioxide as the material for the device layer as taught by Mossberg in the optical device of the Greiner combination since it has been held that the selection of a known material based on its suitability for its intended use is within the skill of one of ordinary skill in the art Sinclair & Carroll Co. v.Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945) See also In reLeshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960) (selection of a known plastic to make a container of a type made of plastics prior to the invention was held to be obvious). MPEP §2144.07. In the instant case, Greiner teaches that different materials can be used to provide a desirable set of device parameters including the refractive indices of the layers (Greiner paragraph [0035]) and Mossberg teaches that titanium dioxide is amongst the suitable materials for use in such an optical device (Mossberg paragraph [0097]).
Claims 14-20 are rejected under 35 U.S.C. 103 as being unpatentable over Greiner et al. US 2020/0271837 A1 (cited in an IDS, hereafter Greiner) in view of Mossberg et al. US 2009/0116790 A1 (hereafter Mossberg).
Regarding claim 14, Greiner teaches “A method of forming (see steps that follow) an optical device (paragraph [0079]: “a first set of specific illustrative examples arranged as in FIG. 1F”), comprising:
forming a material layer stack (Fig. 1F, see elements thereof that follow) comprising:
a device layer (intermediate layer 20) disposed on a substrate (substrate 10 see Fig. 1F), the device layer having a device refractive index of about 1.9 to about 3.5 (1.98 paragraph [0079]: “silicon nitride (nI=1.98; dI=1400 nm)”) and the substrate having a substrate refractive index (1.45 see paragraph [0079]: “the substrate 10 is fused silica (nS=1.45; about 0.35 mm thick),”); and
an outer impedance matching layer (topmost layer 30, which is an impedance matching layer because it has a lower refractive index closer to that of air, than layer 20 does) disposed on the device layer (see Fig. 1F), the outer impedance matching layer having an outer impedance refractive index of about 1.4 to about 1.8 (1.45 paragraph [0079]: “the topmost layer 30 is silicon dioxide (SiO2; nT=1.45; dT=160 nm).”);
etching a portion of the outer impedance matching layer (paragraph [0042]: “The recessed areal regions 103 are formed by spatially selectively etching entirely through the intermediate and topmost layer 20 and 30”)…
etching the device layer through the hardmask (e.g. paragraph [0025]: “a masked etch process that forms recessed areal regions 103 on unmasked areas while leaving non-recessed areal regions 107 on masked areas.” and paragraph [0028]: “the etch mask employed (photo resist, hard mask, or other)” emphasis added, see also paragraph [0042]) to form a plurality of device structures (non-recessed areal regions 107), adjacent device structures of the plurality of device structures defining a gap therebetween (recessed areal regions 103, note that although in paragraph [0079] the regions 107 are circular posts arranged in a grid pattern, they still define gaps between each of the posts even if those gaps are interconnected); and …
wherein the gap is bounded by sidewalls of the plurality of device structures, sidewalls of the outer impedance matching layer, a top surface of the substrate… (see Fig. 1F, the gap is bounded by the sidewalls of 107 including both layers 20 and 30. The gap is also bounded by substrate 10, even though bottom layer 40 is within the gap so defined).”
However, the embodiment of paragraph [0079] and Fig. 1F of Greiner fails to explicitly teach “disposing an encapsulating layer such that the encapsulating layer contacts a top surface of the outer impedance matching layer,
wherein the gap is bounded by… the encapsulating layer.”
However, paragraph [0044] of Greiner teaches “disposing an encapsulating layer (paragraph [0044]: “solid fill medium 70”) such that the encapsulating layer contacts a top surface of the outer impedance matching layer (paragraph [0044]: “the non-recessed areal regions 107 are covered by, the fill medium 70.”), wherein the gap is bounded by… the encapsulating layer (paragraph [0044]: “the recessed areal regions 103 are filled with, and the non-recessed areal regions 107 are covered by, the fill medium 70.” Thus the solid fill medium 70 is present and covers the upper-most end of the gaps, thereby bounding the gaps. The presence of the fill medium protruding into the gaps is not precluded by the claim for at least two reasons (1) “encapsulating” would normally be construed as both conformally filling and covering the underlying structures (2) no other medium is explicitly recited as residing in the gaps and (3) in light of the complicating 112(a) and 112(b) issues explained above, a narrow, literal, interpretation of “bounded by” is unsupportable.).”
Alternatively, Figs. 3A-3F of Greiner teach “disposing an encapsulating layer (a reflector 50) such that the encapsulating layer contacts a top surface of the outer impedance matching layer (see Figs. 3A-3F and paragraph [0067]: “the reflector 50 can be formed on a separate reflector substrate (not shown) and then positioned against the topmost layer 30 of the non-recessed areal regions 107, covering both the recessed and non-recessed areal regions 103 and 107.”), wherein the gap is bounded by… the encapsulating layer (see Figs. 3A-3F and paragraph [0067]: “Retention of the reflector 50 against the non-recessed areal regions 107 can enable use of vacuum, gas, or liquid as the fill medium 70. In those examples the optical element can be immersed in the fill medium while the reflector 50 is secured in place.”).”
Greiner further teaches (paragraph [0066]): “The optical element is structurally arranged so as to receive on at least a portion of the contiguous multitude of areal regions 103 and 107 the incident optical signal 99 propagating through the substrate 10, and to reflect the phase-transformed optical signal 97 to propagate through the substrate 10. The effective phase transformation φeff(x,y) is effected by double-pass transmission through the phase-transforming layer 100 with an intervening reflection by the reflector 50.”
(paragraph [0067]): “In some examples, the reflector 50 can be formed (e.g., grown or deposited) on the topmost layer 30 of the non-recessed areal regions 107 and on a solid fill medium 70 filling the recessed areal regions 103. Such examples typically would require a solid fill medium 70 and some sort of planarization process, after forming the areal regions 103 and 107 and filling with the fill medium 70, before forming the reflector 50… In some examples the fill medium 70 can act as an adhesive, typically in the form a liquid or semiliquid precursor that is then cured to form a solid fill medium and adhesive.”
(paragraph [0088]): “Unless specific arrangements described herein are mutually exclusive with one another, the various implementations described herein can be combined in whole or in part to enhance system functionality or to produce complementary functions.”
Thus it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the specific example of paragraph [0079] having particular choices for the refractive indices as claimed, with an embodiment where a solid fill medium 70 is provided because Greiner teaches that (paragraph [0088]): “Unless specific arrangements described herein are mutually exclusive with one another, the various implementations described herein can be combined in whole or in part to enhance system functionality or to produce complementary functions.” Furthermore, one of ordinary skill in the art would have been motivated to make such a combination in order to protect the optical device structures with a solid encapsulant or to provide a planar surface on which a reflector could be formed or an adhesive by which a reflector could be attaches (paragraph [0067]).
Alternatively, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the specific example of paragraph [0079] having particular choices for the refractive indices as claimed, with a reflector that encapsulates the recessed and non-recessed areas and bound the gaps therebetween as taught by Figs. 3A-3F of Greiner for the purpose of to reflecting the phase-transformed optical signal 97 to propagate through the substrate 10, such that the effective phase transformation φeff(x,y) is effected by double-pass transmission through the phase-transforming layer 100 with an intervening reflection by the reflector 50 as taught by Greiner (paragraph [0066]).
However, Greiner also fails to explicitly teach “etching a portion of the outer impedance matching layer to form a hardmask.”
Note however, that Greiner does teach (paragraph [0042]): “Any suitable spatially selective etch process can be employed (e.g., masked, direct-write, wet etch, dry etch, and so forth).”
Mossberg teaches (claim 14) “A method (see steps below) of forming an optical device (Figs. 12-14), comprising:
forming a material layer stack (1201,1202,1203 or 1301,1302,1303 or 1401,1402,1403) comprising:
a device layer (1201, 1301 or 1401) disposed on a substrate (substrate 1200, 1300, 1400), the device layer having a device refractive index of about 1.9 to about 3.5 (paragraph [0068]: “thick layer 1201 with refractive index n=2.2” paragraph [0070]: “All dimensions, materials, refractive indices and other optical properties in FIGS. 13A and 13B are the same as those of FIG. 12” or paragraph [0071]: “thick layer 1401 of SiN (n=2.2)”) and the substrate having a substrate refractive index (e.g. paragraphs [0068]-[0071]: “The substrate 1200 comprises fused silica or similar material (n=1.446)” and paragraph [0097] teaches “Any suitable material or combination of materials can be employed for forming a grating layer, impedance matching layer, reflective layer, or substrate that exhibits suitable transparency over the relevant operational wavelength range and suitable bulk refractive index. Suitable material can include, are not limited to, silicon, doped silicon, silicon nitride, silicon oxynitride, titanium dioxide, cerium dioxide, aluminum oxide, tantalum pentoxide, aluminum oxynitride, beryllium oxide, bismuth oxide, chromium oxide, germanium, doped germanium, hafnium oxide, magnesium oxide, neodymium oxide, praseodymium oxide, scandium oxide, zinc selenide, zinc sulfide, zirconium oxide, silica, doped silica, borophosphate glass, borosilicate glass, soda lime glass, polymer, beryllium oxide, calcium fluoride, cerium fluoride, cryolite, hafnium fluoride, lanthanum fluoride, strontium fluoride, ytterbium fluoride, ambient atmosphere, air, or inert gas.” emphasis added. Many of these materials have refractive indices between 2.3 and 2.7, for example titanium dioxide has n=2.6, zinc selenide has n=2.6 and zinc sulfide has n=2.35); and
an outer impedance matching layer (1202, 1302 or 1403) disposed on the device layer (see Figs. 12-14), the outer impedance matching layer having an outer impedance refractive index of about 1.4 to about 1.8 (paragraph [0068]: “impedance matching layer 1202 of thickness b=300 nm and refractive index 1.444”; paragraph [0070]: “All dimensions, materials, refractive indices and other optical properties in FIGS. 13A and 13B are the same as those of FIG. 12” or paragraph [0071]: “an upper impedance matching layer 1403 comprising silicon dioxide (n=1.45).”),
etching a portion of the outer impedance matching layer to form a hardmask (paragraph [0069]: “The exemplary optical grating of FIG. 12 can be formed depositing layers 1201 and 1202 on top of layer 1203 on the substrate 1200, then etching through layer 1202, and then etching layer 1201” thus a portion of layer 1202 is etched leaving only the tops of the structures present, i.e. in a manner such that in the next etch step, layer 1202 is a hardmask for the grating layer 1201 beneath it.), and
etching the device layer through the hardmask to form a plurality of device structures (paragraph [0069]: “then etching through layer 1202, and then etching layer 1201”).”
Thus it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the etched topmost layer as a hardmask for the etching of the device layer as taught by Mossberg in the method of Greiner because Greiner teaches that “any suitable spatially selective etch process can be employed (e.g., masked, direct-write, wet etch, dry etch, and so forth).” (paragraph [0042]).
Regarding claim 15, the Greiner – Mossberg combination teaches “The method of claim 14,” and Greiner further teaches “wherein an inner impedance matching layer (bottom layer 40) is disposed between the device layer and the substrate (see Figs. 1C to 1F) and has an inner impedance refractive index (paragraph [0079]: “the bottom layer 40 is aluminum oxide (Al2O3; nB =1.65; dB=160 nm),”) between the substrate refractive index and the device refractive index (1.65 is between 1.45 and 1.98, see paragraph [0079]).”
Regarding claim 16, the Greiner – Mossberg combination teaches “The method of claim 15,” and Greiner further teaches “further comprising etching the inner impedance matching layer through openings formed in the device layer after etching the device layer (paragraph [0048]: “Fabrication of an optical device arranged as in FIGS. 1C or 1D can proceed in a manner similar to methods described above. In some examples, a substrate 10 having continuous bottom, intermediate, and topmost layers 40, 20, and 30 is etched entirely through all three of those layers to form the recessed areal regions 103 and expose the top substrate surface 15 (only partly through the intermediate layer 20, or only partly through the bottom layer 40, in some transversely smaller recessed regions 103 in the example of FIG. 1D), while leaving in place areal portions of the bottom, intermediate, and topmost layers 40, 20, and 30 to form the non-recessed areal regions 107. Any suitable etch process(es) can be employed, including those mentioned elsewhere herein.” Note that the lowest layer is etched after the device layer is inherent because the etching of the lowest layer can only occur after the layer above it has been etched.).”
Regarding claim 17, the Greiner – Mossberg combination teaches “The method of claim 16,” and Greiner further teaches “further comprising removing the hardmask after forming the plurality of device structures (the etching processes used a hard mask, but no hard mask is present in the final device after the fill medium and/or the reflector have been added, thus there exists a step of removing the hard mask).”
Regarding claim 18, the Greiner – Mossberg combination teaches “The method of claim 15,” and Greiner further teaches “wherein the inner impedance refractive index is about 1.4 to about 2.5 (1.65 paragraph [0079]: “the bottom layer 40 is aluminum oxide (Al2O3; nB =1.65; dB=160 nm),”).”
Regarding claim 19, the Greiner – Mossberg combination teaches “The method of claim 18,” and Greiner further teaches “wherein the inner impedance refractive index falls in a range produced by a third formula, wherein the third formula is:
PNG
media_image4.png
20
392
media_image4.png
Greyscale
wherein nsubstrate is the substrate refractive index (paragraph [0079] fused silica n=1.45), ndevice is the device refractive index (paragraph [0079] silicon nitride n=1.98), and ninner.impedance is the inner impedance refractive index (paragraph [0079] aluminum oxide n=1.65, Thus,
PNG
media_image5.png
20
140
media_image5.png
Greyscale
=
1.45
×
1.98
×
0.75
=
1.27
and =
1.45
×
1.98
×
1.25
=
2.118
where 1.65 is within the claimed range).”
Regarding claim 20, the Greiner – Mossberg combination teaches “The method of claim 15,” and Greiner further teaches “wherein the device layer is one or a combination of germanium (Ge), silicon (Si), silicon nitride (Si3N4), titanium dioxide (TiO2), hafnium oxide (HfO2), tantalum pentoxide (Ta205), or scandium oxide (Sc203) (paragraph [0079]: “the intermediate layer 20 is silicon nitride”).”
Response to Arguments
Applicant's arguments filed March 19, 2026 have been fully considered but they are not persuasive.
In the third paragraph of page 9 of 14 of the applicant’s remarks the applicant states that claims 1, 2, 3, 8, 10 and 14 have been amended for purposes of clarity not to distinguish over a reference and thus are entitled a full range of equivalents. The examiner respectfully disagrees. As is apparent from the applicant’s remarks on pages 10-13 the amendments to claims are for the purpose of distinguishing over the applied references Mossberg and Chang.
Further in the third paragraph of page 9 of 14 of the applicant’s remarks the applicant points to specific paragraphs and Figs. as providing support for the amendments to the claims For the reasons explained in the 112(a) rejections above, the examiner disagrees that these portions provide support for the amended or added limitations of claims 1, 2, 3, 10 and 14.
In the second paragraph of page 10 of 14 of the applicant’s remarks the applicant argues that the cancellation of claims 7 and 9 overcome the 35 USC §112 rejections of the previous office action. The examiner agrees, these rejections have been withdrawn.
Applicant’s arguments with respect to claim(s) 1-22 on pages 10-14 (except as noted below) 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.
In the second paragraph of page 13 of 14 of the applicant’s remarks the applicant argues that Mossberg fails to teach that the gaps are bounded by sidewalls of the outer impedance matching layer and further bounded by an encapsulating layer, as required. The examiner agrees that, because Mossberg fails to teach both an outer impedance matching layer and an encapsulating layer together in a single embodiment, this statement is true. However, Mossberg Figs. 5A and 5B do teach an encapsulating layer such that the gaps are bounded by the encapsulating layer. This teaching now forms part of the evidence of obviousness of claim 3 in the alternative that “the gap is air” is interpreted in a manner such that Greiner fails to teach this limitation. However, applicant’s argument is that Mossberg “fails to teach that the gaps are bounded by sidewalls of the outer impedance matching layer and further bounded by an encapsulating layer” not that there are no embodiments of Mossberg that teach an encapsulating layer that bounds the gaps.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CARA E RAKOWSKI whose telephone number is (571)272-4206. The examiner can normally be reached 9AM-4PM ET M-F.
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, Thomas Pham can be reached at 571-272-3689. 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.
/CARA E RAKOWSKI/Primary Examiner, Art Unit 2872
Prosecution Insights