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 .
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.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 05 May, 2026 has been entered.
Response to Amendment
The amendment filed on 05 May, 2026 has been fully considered and entered.
Response to Arguments
Regarding the drawings objections: Applicant's arguments filed 05 May, 2026 have been fully considered but they are not persuasive. Applicant argues that Fig. 6 explicitly shows every claimed feature regarding ridge width. Examiner disagrees. “Grating Number” is not defined anywhere in the disclosure, and it is not a term of art used to convey the meaning that Applicant ascribes to it in the remarks on page 6 of the amendment filed on 05 May, 2026, such as defining a ridge 15 adjacent to ridges 14 and 16. Based on this, it cannot be relied on to support the claim limitations as applicant asserts. A similar argument is made regarding Fig. 5 illustrating the claimed trench width relationships. For the same reason, Examiner disagrees.
Regarding the rejections under 35 U.S.C. 112(a): Applicant's arguments filed 05 May, 2026 have been fully considered but they are not persuasive. Applicant argues that the Examiner uses an incorrect standard for what would reasonably convey the meaning of a term to a person skilled in the art. Examiner disagrees. As stated in the final Office Action mailed on 05 February, 2026, “Grating Number” is not defined anywhere in the disclosure, and it is not a term of art used to convey the meaning that Applicant ascribes to it. Based on this, it cannot be relied on to support the new limitations relating to the claimed ridge width relationships and trench width relationships. The response from Applicant filed 06 April, 2026 asserts that “In the field of photonics, a “grating” is a sequence of physical elements. Numbering these elements sequentially on a graph is the standard technical method for denoting their spatial order. A PHOSITA would exclusively interpret “Grating Number N” as being physically adjacent to elements “N-1” and “N+1.”” This is an unsubstantiated claim, and since Applicant provided no reference nor further support from the originally filed specification for the newly added claim limitations, Examiner found the argument to be unconvincing. Moreover, Examiner is providing several references (Kobayashi, US 2019/0113663, paragraph 0049; Kittaka et al. US 2008/0107388, paragraph 0005; and Augustsson US 2002/0006249, paragraph 0052) which demonstrate “grating number” being used to convey different meanings. For instance, entire gratings can be identified by a grating number, as evidenced by Augustsson paragraph 0052. An alternative interpretation that a PHOSITA could reach in reading the present disclosure, given the lack of description relating to the figure, would be that the grating numbers refer to different gratings. This would not convey physical adjacency, as asserted by applicant. Therefore, a person of ordinary skill in the art would not exclusively interpret “Grating Number N” as being physically adjacent to elements “N-1” and “N+1”. Since the originally filed disclosure is unclear, the claims were properly rejected under 35 U.S.C. 112(a).
Regarding examples of peer-reviewed articles that use the term “grating number”: Applicant's arguments filed 05 May, 2026 have been fully considered but they are not persuasive. Applicant has provided only partial citations (indicating the journal name, the volume and the issue number without identifying the article) to two of the alleged 9 references which use “grating number” in a similar way. If Applicant intends to use these as evidence for Examiner to reconsider the position that grating number does not convey a clear, explicit meaning in the art, such that it can convey that meaning in the present application without being explicitly defined or described, Applicant should provide the references for Examiner to review and they should be made of record. Screenshots of plots have not convinced Examiner that “grating number” is a well-known and clear term of art used to convey adjacency.
Regarding prior art rejections: Applicant’s arguments with respect to claims 1-20 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.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the first ridge having “a width that is narrower than two adjacent ridges” and the second ridge having “a width that is wider than two adjacent ridges” (as claimed in claims 1 and 14) must be shown or the feature(s) canceled from the claim(s). Likewise, the first trench having “a width that is narrower than two adjacent trenches” and a trench having a width “that is wider than two adjacent trenches” (as claimed in claim 9) must be shown or the features canceled from the claims. No new matter should be entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Objections
Claim 12 is objected to because of the following informalities: there is a dash between “index” and “than” that should not be present. Appropriate correction is required.
Claim Rejections - 35 USC § 112
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 1-20 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 and 14: Claims 1 and 14 recite “a first ridge has a width that is narrower than two adjacent ridges and a second ridge has a width that is wider than two adjacent ridges”. Applicant points to Fig. 6 as well as paragraphs 71 and 76 for support for this new limitation. Fig. 6 is a graph showing “Ridge Width (nm)” as a function of “Grating Number”. Paragraph 71 identifies Fig. 6 as “a chart of ridge withs of the embodiment of the first grating”. Paragraph 76 describes that non-uniform gratings have periods, trench widths, and ridge widths with variation from an average value. Neither of these paragraphs, nor the figure, specifically demonstrate “a first ridge has a width that is narrower than two adjacent ridges and a second ridge has a width that is wider than two adjacent ridges”. “Grating Number” is not defined anywhere in the disclosure, and it is not a term of art used to convey the meaning that Applicant ascribes to it in the remarks on page 7, paragraph 2, of the amendment filed on 12 January, 2026, such as defining a “ridge 15” adjacent to “ridges 14 and 16”. Based on this, it cannot be relied on to support the new limitations added to claims 1 and 14. Therefore, the new limitations introduce new matter.
Regarding claim 9: Claim 9 recites “a first trench has a width that is narrower than two adjacent trenches and a trench has a width that is wider than two adjacent trenches”. Applicant points to Fig. 5 as well as paragraphs 71 and 76, for support for this new limitation. Following the same reasoning described above, Fig. 5 and paragraphs 71 and 76 cannot be relied on to support the new limitation added to claim 9. Therefore, the new limitation introduces new matter.
Regarding claims 2-9, 10-13, and 15-20: Dependent claims 2-9, 10-13, and 15-20 inherently contain all of the deficiencies of any base and intervening claims from which they depend.
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 9-13 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 claim 9: Claim 9 recites the limitations “a trench has a width that is wider than two adjacent trenches” and “ridge has a width that is narrower than two adjacent ridges”. It is unclear if these are related to the first set of trenches and ridges, respectively, or if they are additional elements required by this claim. For the purpose of examination, “a trench” is interpreted as “a second trench”, based on the widths of the first set of trenches varying within the same part of the claim; however, the “ridge has a width” limitation is understood to mean “a first ridge of the first set of ridges” since this limitation does not logically flow from the widths of the first set of trenches varying, so further clarification is needed in the claim.
Regarding claim 10: the limitation “the second trench” lacks proper antecedent basis. However, as best understood by the examiner, the recitation in claim 9 of “a trench” is understood to refer to “a second trench”, being the second trench referred to here.
Regarding claims 10-13: Dependent claims 10-13 inherently contain all of the deficiencies of any base or intervening claims from which they depend.
Note: The following rejections are based upon the claims as best understood by Examiner.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-4, 7-10, and 12-13 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Michaels et al. (Inverse Design of Near Unity Efficiency Perfectly Vertical Grating Couplers, arXiv 2018; DOI: 10.48550/arXiv.1705.07186; copy attached to this Office Action; hereinafter Michaels).
Regarding claim 1: Michaels discloses A system for optical communication, comprising: a waveguide (see waveguide in Annotated Fig. 4) having a core (silicon core, see Fig. 3) of higher refractive index material than a cladding (SiO2 cladding, see Fig. 3), the waveguide disposed on a substrate (Fig. 3, bottom layer of SiO2 is considered to be a substrate), wherein the core is configured to guide light along a first propagation direction (light is guided along the x-direction in the waveguide, as best shown in Fig. 1); and a coupler (two-layer grating; see left col., first paragraph of page 2) comprising: a first grating (see annotated Fig. 4) formed in the higher refractive index material (Figs. 1, 3, and 4 show this), wherein: the first grating comprises a first set of ridges separated by a first set of trenches (see annotated Fig. 4) and widths of the first set of ridges are non-uniform such that widths of the first set of ridges have variation from an average width (Fig. 4 shows this), such that widths of the first set of ridges have variation from an average width (Fig. 4 shows this) so that a first ridge has a width that is narrower than two adjacent ridges (see annotated Fig. 4; the drawings are accompanied by a scale bar; therefore, they are drawn to scale; in the righthand inset of the annotated figure, three consecutive ridges are labeled a, b, and c, and the dotted scale bar represents the length of ridge b; in the main part of the figure, an additional ridge is labeled d and it is visibly smaller than ridge c; ridge c is considered to be a first ridge, and it is narrower than ridges a and b, considered to be two adjacent ridges, as they are adjacent to each other and to ridge c) and a second ridge has a width that is wider than two adjacent ridges (see annotated Fig. 4; ridge b is considered to be a second ridge, and it is wider than ridges c and d, considered to be two adjacent ridges, as they are adjacent to each other and to ridge b) a second grating (see Fig. 4, top layer of the two-layer grating is a second grating), wherein: the second grating comprises a second set of ridges separated by a second set of trenches (see annotated Fig. 4); the first set of ridges is between the substrate and the second set of ridges (annotated Fig. 4 shows this); the second set of ridges partially overlap the first set of ridges (Fig. 4 shows this); the second set of ridges partially overlap the first set of trenches (Fig. 4 shows this); the coupler is configured to couple light out of the waveguide along a second propagation direction (best represented in Fig. 1, the direction of the fiber core); and the second propagation direction is not parallel with the first propagation direction (the direction is perpendicular).
Regarding claim 2: Michaels disclosesThe system of claim 1 (as applied above), further comprising an optical fiber positioned to receive light along the second propagation direction (see Fig. 4, fiber core; additionally, see Fig. 1 showing the light path).
Regarding claim 3: Michaels disclosesThe system of claim 1 (as applied above), wherein the second propagation direction is orthogonal to the first propagation direction (Fig. 1 shows this).
Regarding claim 4: Michaels disclosesThe system of claim 1 (as applied above), wherein the first ridge is adjacent to the second ridge (as shown in annotated Fig. 4, ridges b and c are adjacent to each other).
Regarding claim 7: Michaels disclosesThe system of claim 1 (as applied later), wherein the first set of ridges, the second set of ridges, the first set of trenches, and the second set of trenches each have widths greater than or equal to 170 nm (see scalebar in rightmost inset of Fig. 4; each of these features is shown to have widths greater than or equal to 170 nm within the inset region).
Regarding claim 8: Michaels disclosesThe system of claim 7 (as applied above), wherein the coupler has a coupling efficiency of better than -2 dB (see caption of Fig. 4).
Regarding claim 9: Michaels disclosesAn optical device comprising: a substrate (Fig. 3, bottom layer of SiO2 is considered to be a substrate); a first set of ridges (see annotated Fig. 4, set of ridges of the first grating) separated by a first set of trenches (see annotated Fig. 4, set of trenches of the first grating), wherein widths of the first set of trenches and the first set of ridges are non-uniform (Fig. 4 shows this), such that widths of the first set of trenches have a variation from an average width (Fig. 4 shows this) so that a first trench has a width that is narrower than two adjacent trenches (in annotated Fig. 4, trench e has a width that is narrower than trenches f and g, considered to be adjacent trenches as they are adjacent to each other and to trench e), a second trench has a width that is wider than two adjacent trenches (in annotated Fig. 4, trench g has a width that is wider than trenches f and e, considered to be adjacent trenches as they are adjacent to each other and to trench g), and a first ridge of the first set of ridges has a width that is narrower than two adjacent ridges (see annotated Fig. 4, ridge c has a width that is narrower than ridges a and b, considered to be adjacent ridges, since they are adjacent to each other and to ridge c); and a second set of ridges (see annotated Fig. 4, set of ridges of the second grating), wherein: the second set of ridges are disposed on the first set of ridges (annotated Fig. 4 shows this), such that the first set of ridges are between the substrate and the second set of ridges (annotated Fig. 4 shows this); and the second set of ridges are offset from the first set of ridges (Fig. 4 shows this).
Regarding claim 10: Michaels disclosesThe optical device of claim 9 (as applied above), wherein the first set of ridges forms a first grating (the first set of ridges inherently forms a first grating), and the first grating has a non-uniform spacing between ridges (Fig. 4 shows this), and there are no more than two trenches between the first trench and the second trench (as best understood, the second trench refers to “a trench” as claimed in claim 9; the first and second trenches therefore correspond to trenches e and g; there is only one trench between trenches e and g, i.e. no more than two trenches).
Regarding claim 12: Michaels disclosesThe optical device of claim 9 (as applied above), wherein: the first set of ridges are separated by a first set of trenches (Fig. 4 shows this), as part of a first grating; the first set of trenches are filled with an insulating material that has a lower refractive index-than the first set of ridges (see Fig. 3, the first set of trenches are filled with SiO2, an insulating material that has a lower refractive index than the first set of ridges, which are made of silicon); the second set of ridges are separated by a second set of trenches (Fig. 4 shows this), as part of a second grating; the second set of ridges partially overlap the first set of ridges (Fig. 4 shows this); and the second set of ridges partially overlap the first set of trenches (Fig. 4 shows this), so that subwavelength structures are formed (see abstract, the wavelength of interest is 1550nm, whereas as shown in Fig. 4, the partially overlapping first and second test of trenches form features that are less than 500 nm; therefore, these features are subwavelength structures).
Regarding claim 13: Michaels disclosesThe optical device of claim 12 (as applied above), wherein: the first set of ridges are made in a core of a waveguide (see Fig. 3 and left column, last full paragraph of page 4); light is coupled out of the waveguide using the first grating and the second grating (see last paragraph of page 1 and continued onto page 2; the two-layer grating is considered to comprise the first grating and the second grating); the first set of ridges and the second set of ridges are configured to cause light from the waveguide to constructively interfere in an upward direction and destructively interfere in a downward direction, thus enhancing the coupling efficiency of light coupled out of the waveguide (see last paragraph of page 1 and continued onto page 2); and the upward direction is a direction from the first grating toward the second grating (the upward direction in Figs. 1, 3, and 4 corresponds to this direction).
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.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Michaels et al. (Inverse Design of Near Unity Efficiency Perfectly Vertical Grating Couplers, arXiv 2018; DOI: 10.48550/arXiv.1705.07186; copy attached to this Office Action; hereinafter Michaels).
Michaels discloses the optical device of claim 10, as applied above. The non-uniform spacing is characterized by a variation in the ridge width, corresponding to a variation in the spacing between trenches. In the plot shown in Fig. 6, the average duty factor appears to be around 0.7 for the bottom layer, and the average period appears to be around 0.62 microns; this corresponds to an average spacing between trenches of about 0.43 microns. The leftmost points of the plot, also for the bottom layer, appear to correspond to a duty factor greater than 0.95 and a period of around 0.57 microns, corresponding to at least one spacing between adjacent trenches having a width of 0.54 microns. This corresponds to a value that is around 125% of an average value of spacing between two adjacent trenches. Based on this, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to make the Michaels device having the claimed property of at least one spacing between adjacent trenches having a width that is equal to or greater than 125% of an average value of spacing between two adjacent trenches, and one of ordinary skill in the art could expect a device having such a property to operate substantially similarly to the device disclosed by Michaels, for the purpose of optimizing the outcoupling efficiency of the device.
Claims 1, 14-16, and 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over Xiao et al. (CN 112230339 A; copy and translation attached to Office Action mailed on 05 February, 2026; hereinafter Xiao) in view of Michaels et al. (Inverse Design of Near Unity Efficiency Perfectly Vertical Grating Couplers, arXiv 2018; DOI: 10.48550/arXiv.1705.07186; copy attached to this Office Action; hereinafter Michaels).
Regarding claim 1: Xiao discloses A system for optical communication, comprising: a waveguide (Xiao Fig. 7, waveguide comprises silicon dioxide middle layer 20, silicon top layer 30, silicon dioxide coating layers 32 and 42; see last paragraph of page 4 of the attached translation to the first paragraph of page 5 of the attached translation) having a core (silicon; see last paragraph of page 4 of the attached translation) of higher refractive index material than a cladding (silicon dioxide middle layer 20 and silicon dioxide coating layers 32 and 42 are a cladding with a lower refractive index than the silicon core), the waveguide disposed on a substrate (Xiao Fig. 7, substrate 10; see last paragraph of page 4 of the attached translation), wherein the core is configured to guide light along a first propagation direction (light will be guided due to the refractive index boundaries of the core and cladding layers); and a coupler (Xiao Fig. 1, grating coupler includes regions 31, 32, 41, and 42; see last paragraph of page 5 to third paragraph of page 6 of the attached translation) comprising: a first grating (Xiao Fig. 1, formed of ridges 31, separated by regions 32) formed in the higher refractive index material (silicon; see last paragraph of page 5 of translation), wherein: the first grating comprises a first set of ridges separated by a first set of trenches (Fig. 1, ridges 31 separated by trenches filled with coating layer 32)
Xiao further teaches a second grating (Xiao Fig. 1, formed of ridges 41, separated by regions 42), wherein: the second grating comprises a second set of ridges separated by a second set of trenches (Xiao, ridges 41 separated by trenches filled with coating layer 42); the first set of ridges is between the substrate and the second set of ridges (Xiao Fig. 1 shows this); the second set of ridges partially overlap the first set of ridges (Xiao Fig. 1, see portions of ridges 41 above ridges 31); the second set of ridges partially overlap the first set of trenches (Xiao Fig. 1, see portions of ridges 41 above regions 32); the coupler is configured to couple light out of the waveguide along a second propagation direction (the grating coupler is capable of coupling light out of the waveguide; see note below regarding presumed inherency); and the second propagation direction is not parallel with the first propagation direction (the grating coupler is capable of coupling light out of the waveguide in a different direction than the propagation direction within the waveguide, since the diffraction grating changes the direction of the coupled light; see note below regarding presumed inherency).
Xiao fails to disclose “widths of the first set of ridges are non-uniform such that widths of the first set of ridges have variation from an average width, such that widths of the first set of ridges have variation from an average width so that a first ridge has a width that is narrower than two adjacent ridges and a second ridge has a width that is wider than two adjacent ridges”. However, before the effective filing date of the claimed invention, Michaels, also related to out of plane grating couplers designed to interface a photonic integrated circuit with an optical fiber, taught that the coupling efficiency of a grating coupler could be better tailored by varying the coupling strength across the grating, and that varying the coupling strength could be achieved by varying the widths of ridges, such that widths of the first set of ridges have variation from an average width, such that widths of the first set of ridges have variation from an average width so that a first ridge has a width that is narrower than two adjacent ridges and a second ridge has a width that is wider than two adjacent ridges (see rejection of claim 1 under 35 U.S.C. 102(a) above). Based on the teachings of Michaels, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the Xiao device so that the ridge widths in the first grating are non-uniform, such that widths of the first set of ridges have a variation from an average width so that a first ridge has a width that is narrower than two adjacent ridges and a second ridge that has a width that is wider than two adjacent ridges, in order to optimize the coupling efficiency when coupling light from a photonic integrated circuit to an optical fiber (see Michaels abstract and introduction).
Regarding claim 14: Xiao disclosesA method for fabricating an optical coupler, the method comprising: etching a first set of trenches in a device layer to form a first set of ridges of a first grating (see abstract; etching the silicon top layer; see also Figs. 2-3, trenches are formed, at least including a first set of ridges of a first grating); filling the first set of trenches with a material having a lower refractive index than the device layer (11-12th paragraph, page 6 of attached translation, first cladding 32 may be deposited by a PECVD process; 2nd paragraph, page 6 of attached translation, silicon dioxide; silicon dioxide has a lower refractive index than silicon; Fig. 4);, depositing an overlay material on the first set of ridges and on the material having a lower refractive index than the device layer (Fig. 5; paragraph 15 of page 6 of the attached translation); and etching a second set of trenches in the overlay material to form a second set of ridges of a second grating (see abstract; etching the Poly-si layer), wherein the second set of ridges partially overlaps the first set of ridges and partially overlaps the insulating material in the first set of trenches.
Xiao fails to disclose “widths of the first set of ridges are non-uniform, such that widths of the first set of ridges have a variation from an average width so that a first ridge has a width that is narrower than two adjacent ridges and a second ridge that has a width that is wider than two adjacent ridges”. However, before the effective filing date of the claimed invention, Michaels, also related to out of plane grating couplers designed to interface a photonic integrated circuit with an optical fiber, taught that the coupling efficiency of a grating coupler could be better tailored by varying the coupling strength across the grating, and that varying the coupling strength could be achieved by varying the widths of ridges, such that widths of the first set of ridges have variation from an average width, such that widths of the first set of ridges have variation from an average width so that a first ridge has a width that is narrower than two adjacent ridges and a second ridge has a width that is wider than two adjacent ridges (see rejection of claim 1 under 35 U.S.C. 102(a) above). Based on the teachings of Michaels, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the Xiao device so that the ridge widths in the first grating are non-uniform, such that widths of the first set of ridges have a variation from an average width so that a first ridge has a width that is narrower than two adjacent ridges and a second ridge that has a width that is wider than two adjacent ridges, in order to optimize the coupling efficiency when coupling light from a photonic integrated circuit to an optical fiber (see Michaels abstract and introduction).
Regarding claim 15: Modified Xiao teachesThe method of claim 14 (as applied above), wherein the overlay material is index matched with the device layer (Poly-Si and silicon are considered to be index matched, as evidenced by Xiao paragraphs 0017, 0058, and 0089 of the present disclosure, poly-si is used for the index-matching overlay material and silicon is used for the device layer in the present disclosure, matching the prior art materials; therefore, they are assumed to have the same properties, see note below regarding presumed inherency).
When a structure recited in a reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. See MPEP 2112.01. Modified Xiao teaches a grating coupler that is substantially identical to that of the claimed invention, therefore the claimed property of index matching between the overlay material and the device layer is presumed to be inherent. The burden is on the applicant to show that the prior art device does not inherently possess the claimed properties. See MPEP 2112.01.
The examiner notes that if the claimed structure does not inherently possess the claimed properties, then the claims would be incomplete for omitting essential structural cooperative relationships of elements, such omission amounting to a gap between the necessary structural connections necessary to clearly and precisely define the invention, wherein the structure necessary to provide the claimed properties is essential.
Regarding claim 16: Modified Xiao teachesThe method of claim 15 (as applied above), wherein the overlay material is amorphous silicon, polysilicon, or dielectric material (polysilicon; see Xiao abstract).
Regarding claim 19: Modified Xiao teachesThe method of claim 14 (as applied above), wherein the first set of ridges of the first grating have a non-uniform period (Michaels Fig. 4 shows this; therefore, when making the modification described above to improve coupling efficiency, the modified Xiao device would have this feature).
Regarding claim 20: Modified Xiao teachesThe method of claim 14 (as applied above), the method further comprising etching the device layer to form a waveguide optically coupled with the first grating (see Xiao Figs. 2-3, during the etching steps illustrated in Figs. 2-3, the first grating is formed, as well as the waveguide which is optically coupled with the first grating; therefore, the disclosed method includes both etching a first set of trenches in a device layer to form a first set of ridges of a first grating, and etching the device layer to form a waveguide optically coupled with the first grating).
Claims 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Xiao et al. (CN 112230339 A; copy and translation attached to this office action; hereinafter Xiao) in view of Michaels et al. (Inverse Design of Near Unity Efficiency Perfectly Vertical Grating Couplers, arXiv 2018; DOI: 10.48550/arXiv.1705.07186; copy attached to this Office Action; hereinafter Michaels) and further in view of Shiozaki et al. (US 2005/0152037; Shiozaki).
Regarding claim 17: Modified Xiao teaches the method of claim 14, as applied above. Xiao fails to teach that the method further comprises implementing a numerical method to optimize shift and individual widths of ridges of the first set of ridges and the second set of ridges, such that individual ridges of the first set of ridges have the variation from the average width. However, Shiozaki, related to the design of grating elements, including multilayered grating elements (see Fig. 9) teaches using a numerical optimizing technique including a genetic algorithm to optimize the grating period, the height of the grating, and the duty ratio (see paragraph 0102). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to implement a numerical method to optimize the shift and individual widths of ridges and slits of the first set of ridges and the second set of ridges, since these are result effective variables, affecting the loss of the grating, and since such methods were previously known to be used to design the geometric features of grating elements. Doing so would allow one of ordinary skill in the art to optimize these result effective variables by known methods.
Regarding claim 18: Modified Xiao teachesThe method of claim 17 (as applied above), wherein the numerical method comprises a genetic algorithm or a particle swarm optimization (see paragraph 0102).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Michaels et al. (Inverse Design of Near Unity Efficiency Perfectly Vertical Grating Couplers, arXiv 2018; DOI: 10.48550/arXiv.1705.07186; copy attached to this Office Action; hereinafter Michaels) in view of Klamkin et al. (US 2017/0207600; hereinafter Klamkin).
Michaels discloses the system of claim 1, as applied above. Michaels fails to disclose that the first grating is a blazed grating. However, Klamkin, also related to the grating couplers (see paragraph 0007 and 0093), teaches that blazed gratings can be used, as an alternative to gratings having rectangular ridges, and that they can enhance the coupling efficiency of the grating (see paragraph 0093). In order to enhance the coupling efficiency of the grating to a desired output, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the Michaels device by forming the first grating as a blazed grating.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Xiao et al. (CN 112230339 A; copy and translation attached to this office action; hereinafter Xiao) in view of Michaels et al. (Inverse Design of Near Unity Efficiency Perfectly Vertical Grating Couplers, arXiv 2018; DOI: 10.48550/arXiv.1705.07186; copy attached to this Office Action; hereinafter Michaels) and further in view of Na et al. (US 2011/0243492; hereinafter Na).
Modified Xiao teaches the system of claim 1, as applied above. Xiao further discloses that the second set of ridges comprises a non-single-crystal semiconductor (polysilicon, see abstract), and that the higher refractive index material of the first set of ridges comprises a semiconductor (silicon), and the first set of trenches are filled with material having a lower refractive index than the single-crystal semiconductor material (silicon dioxide has a lower refractive index than silicon). Xiao fails to disclose that the higher refractive index material is a single-crystal semiconductor. However, Xiao does distinguish between “silicon”, the higher refractive index material, and “Poly-Si”, the overlay material, suggesting they may have different forms. Na, also related to grating couplers for coupling light with waveguides, teaches that monocrystalline silicon was known to be a suitable material for forming waveguides and grating couplers (see paragraphs 0043-0044). It has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416. Since it was previously taught by Na that monocrystalline silicon is a suitable material for grating couplers and waveguides, and since Xiao discloses that the high refractive index material is silicon, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to use monocrystalline silicon for the high refractive index material in the Xiao device, to obtain a more uniform structure.
Conclusion
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/KIRSTEN D. ENDRESEN/Examiner, Art Unit 2874
/THOMAS A HOLLWEG/Supervisory Patent Examiner, Art Unit 2874
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