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 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.
DETAILED ACTION
Applicant’s amendments and remarks filed 1/6/26 are acknowledged. Claims 1 – 3, 6, 8, 9, and 12 – 14 have been amended and claims 10 and 11 canceled. Claims 1 – 9 and 12 – 16 are pending.
Response to Amendments / Arguments
Applicant's amendments have obviated the previously-raised rejection of claim 12 under 35 USC 112.
Applicant's amendments have obviated the previously-raised rejections under 35 USC 102 and necessitated new rejections under 35 USC 103(a), as detailed below.
Applicant's arguments regarding the amended claims versus the previously-raised rejections under 35 USC 103(a) have been fully considered but they are not persuasive. Furthermore, the arguments are in part moot in view of the new grounds of rejections, as necessitated by Applicant’s amendments. Specifically, Applicant incorporated new limitations in independent claims 1, 13, and 14, the limitations comprising, as alternatives, limitations similar/identical to those of canceled claims 10 and 11. Accordingly, the Examiner additionally applies the Overvig reference to cover both alternative design choices for meta-atoms.
Amended claims 1, 13, and 14:
(a) Applicant argues that “Ding's meta-atoms are disclosed to be metal-insulator-metal nanobars rather than "dielectric pillars or air apertures." A person having ordinary skill in the art would recognize that a disclosure of sandwiched nanobars, e.g., featuring a vertically layered structure, does not disclose or suggest the feature of "dielectric pillars or air apertures," as recited in amended claim 1” (2nd para. on p. 7 of the Remarks).
The Examiner respectfully disagrees and notes that amended claims 1, 13, and 14 recite only that a plurality of meta-atoms include, but not necessarily consist of, at least one of dielectric pillars and air apertures etched in the high refractive index layer. The nanobars described by Ding each include a middle layer of silicon, which is one of high-index materials as defined by the instant specification and recited by claim 12. Ding considers that the thickness of the middle layer of silicon can be equal to that of the Au layers sandwiching it and that the height/length of each nanobar can be 3+ times greater than its transverse size (para. bridging columns on p. 399). In that case, the middle layer of silicon has a height greater than is transverse size and is shaped as a pillar.
Figure 1 of Ding indicates that the nanobars are shaped as protruding nanoobjects and surrounded by air. While Ding does not detail a particular method of shaping the nanobars, a variety of suitable/workable methods (e.g., etching, nano-printing, etc) are well known in the art. The Overvig reference us applied to expressly identify etching an etching process to form air-filled apertures etched in a high-refractive-index layer (of silicon, i.e., the same material as in Ding).
(b) Applicant’s arguments drawn to Overvig (pp. 7 – 8) are not persuasive on either technical grounds (as attempting to oppose a metasurface in Ding and a metasurface in Overvig) or legal grounds (as not addressing the essence of the applied combination).
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 of this title, 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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1 – 9 and 12 – 16 are rejected under 35 U.S.C. 103 as being unpatentable over “Metasurface-Dressed Two-Dimensional on-Chip Waveguide for Free-Space Light Field Manipulation” by Ding et al, ACS Photonics, vol. 9, pp. 398−404, January 2022 (hereinafter Ding) in view of “Multifunctional Nonlocal Metasurfaces” by Overvig et al, PHYSICAL REVIEW LETTERS, vol. 125, paper 017402, pp. 1 – 6, 2020 (hereinafter Overvig).
Regarding claims 1 and 12, Ding describes (Fig. 1; Abstract; pp. 398 – 399) an integrated metasurface device for conversion between a waveguide mode TE00 (in a silicon waveguide) and a free-space optical wave (“An off-chip focusing function was demonstrated numerically and experimentally” at last para. on p. 402) with a designer wavefront (e.g., a converging wavefront of a focused free-space beam; “We show that a metasurface-coated two-dimensional (2D) slab waveguide enables the generation of arbitrary complex light fields by combining the extreme versatility and freedom on the wavefront control of optical metasurfaces” in the Abstract; also 3rd para. on p. 398), comprising:
a) a thin waveguide (the narrow waveguide portion in Fig. 1; a single-mode Si waveguide on a SiO2 substrate; “An edge-coupling port connected with a single-mode waveguide was used to eliminate higher-order propagation modes” at the left column on p. 400);
b) a waveguide taper (as seen in Fig. 1; “The single-mode waveguide was immediately followed by a taper that could adiabatically convert the fundamental TE00 mode from the single-mode waveguide into a TE00 mode with extended width in the slab waveguide” at the right column on p. 400, emphasis added);
c) a leaky-wave metasurface defined within a high refractive index (silicon) layer of dielectric material (“In this work, we extended the capability of using a metasurface to control scattered light from 1D to 2D. By placing metal−dielectric−metal metaatoms on top of a slab waveguide, we can tune the phase of scattered light covering 2π” at para. bridging pp. 398 – 399; “The nanoantennas we used here are metal−insulator−metal (MIM) sandwiched nanobars … A sandwiched nanobar composed of stacked Au, Si, and Au layers, with a thickness of 30 nm for each layer, was placed on top of a 500 nm thick Si slab waveguide on a SiO2 substrate” at 1st complete para. on p. 399, emphasis added); and
d) a low refractive index substrate (of silicon dioxide; “A sandwiched nanobar composed of stacked Au, Si, and Au layers, with a thickness of 30 nm for each layer, was placed on top of a 500 nm thick Si slab waveguide on a SiO2 substrate” at 1st complete para. on p. 399”, emphasis added), the high refractive index layer deposited thereon.
The nanobars described by Ding each include a middle layer of the high-refractive-index (silicon) material. Ding considers that the thickness of the middle layer of silicon can be equal to that of the Au layers sandwiching it and that the height/length of each nanobar can be 3+ times greater than its transverse size (para. bridging columns on p. 399). In that case, the middle layer of silicon has a height greater than is transverse size and is shaped as a (dielectric) pillar.
Further, Figure 1 of Ding indicates that the nanobars are shaped as protruding nanoobjects and surrounded by air. While Ding does not detail a particular method of shaping the nanobars, a variety of suitable/workable methods (e.g., etching, nano-printing, etc) are well known in the art. In particular, Overvig describes (Figs. 1 and 2; pp. 1 – 4) a leaky-wave metasurface (coupling optical radiation to/from free-space, as shown in Fig. 1a) that comprises a plurality of meta-atoms (Figs. 1a, 1b, and 2a) including dielectric pillars (1st complete para. on p. 017402-2) and air apertures/holes formed by etching a high-refractive index layer (silicon, i.e., the same material as in Ding) (“We begin by considering a two-dimensional PCS composed of air holes in a silicon slab, sitting on a silicon dioxide substrate” at para. bridging pp. 1 – 2; “Figure 2(a) schematically depicts such a metasurface consisting of a slab of silicon etched with elliptical holes that encode a phase gradient” at para. bridging columns on p. 017402-3 of Overvig, emphasis added). It would have been obvious to a person of ordinary skill in the art before the dielectric pillars and air apertures in Ding can be formed by etching, as a suitable/workable method that is well known in the art, generally rendered obvious by Ding, and expressly identified by Overvig.
In light of the foregoing analysis, the Ding – Overvig combination teaches expressly or renders obvious all of the recited limitations.
Regarding claim 2, Ding describes that the thin (silicon) waveguide supports a (single) waveguide mode TE00 (“An edge-coupling port connected with a single-mode waveguide was used to eliminate higher-order propagation modes” at the right column on p. 400).
Regarding claim 3, Ding describes (Fig. 1) that the waveguide taper converts the (single) waveguide mode TE00 into a slab waveguide mode TE00 in the form of a sheet of light (as illustrated in Fig. 1; “The single-mode waveguide was immediately followed by a taper that could adiabatically convert the fundamental TE00 mode from the single-mode waveguide into a TE00 mode with extended width in the slab waveguide” at the right column on p. 400).
Regarding claim 4, Ding describes (Fig. 1) that the leaky-wave metasurface comprises a plurality of meta-units (groups of nanobars; “The nanoantennas we used here are metal−insulator−metal (MIM) sandwiched nanobars … A sandwiched nanobar composed of stacked Au, Si, and Au layers, with a thickness of 30 nm for each layer, was placed on top of a 500 nm thick Si slab waveguide on a SiO2 substrate” at 1st complete para. on p. 399, emphasis added).
Regarding claim 5, Ding describes (Fig. 1) that each meta-unit comprises at least two sets of anisotropic meta-atoms (“… an arbitrary phase profile expanding through the 2D functional area could be realized by spatially arranging this set of three nanoantennas with different geometrical parameters” at 1st complete para. on p. 399, emphasis added), and wherein:
a) the two sets have a subwavelength offset between each other (“The period along and perpendicular to the propagation direction is 220 and 440 nm, respectively” at para. bridging pp. 399 – 400; “the desired operational wavelength (1550 nm)” at 1st complete para. on p. 399);
b) the two sets have different magnitudes of perturbation (due to different sizes of bars; “Based on the phase/amplitude-geometries map, three different nanobar geometries with the same scattered electric field amplitude and phases equaling 2π/3, 0, and −2π/3, respectively, were selected as the building blocks for the metasurface” at 1st complete para. on p. 399, emphasis added).
and/or
c) the two sets have different orientations of perturbation (as seen in Fig. 1).
Regarding claim 6, Ding describes, by way of example but not limitation, a metasurface defined by a particularly designed set of meta-units/nanobars (for off-chip/free-space focusing). Ding makes a general statement that the same approach of using a 2D metasurface integrated on a slab waveguide and driven by a guided wave can be applied to a wide variety of other designs of 2D metasurfaces. While Ding does not detail a 2D metasurface configured for decomposing light into two orthogonal polarization components, Overvig describes (Figs. 1 and 2; pp. 1 – 4) a 2D metasurface configured for decomposing light into two orthogonal polarization components (which produce a right-hand circularly polarized (RCP) wave and a left-hand circularly polarized (LCP) wave when the relative phase difference between two orthogonal polarization components is ±90 degrees), and modifying them.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the waveguide structure in Ding can be used for providing light to a 2D metasurface of Overvig and enabling a device for polarization manipulation/transformation (Fig. 2 and its caption; 4th para. on p. 1; para. bridging columns on p. 2; entire p. 3 of Overvig).
The Ding – Overvig combination considers an integrated metasurface device, wherein the slab waveguide mode T00 is decomposed into two orthogonal standing waves (para. bridging columns on p. 4; para. bridging columns on p. 5), wherein the two sets of meta-atoms (e.g., shown in Figs. 2 and 4) independently control the two standing waves RCP,LCP, converting each standing wave into a surface emission with independent amplitude and polarization orientation, and wherein the two surface emissions merge into a single free-space wave (as shown in Fig. 2a) with completely and independently controllable amplitude, phase, polarization orientation, and polarization ellipticity at each point over the wavefront of the free-space wave (Fig. 4 and its caption; 4th para. on p. 1; para. bridging columns on p. 3; para. bridging pp. 4 – 5 and following para.).
In light of the foregoing analysis, the Ding – Overvig combination teaches expressly or renders obvious all of the recited limitations.
Alternatively, the teachings of Ding (a 2D metasurface integrated on a slab waveguide and driven by a guided wave in it) can be applied to the structure in Overvig and change free-space excitation of the metasurface to guided-wave excitation.
Regarding claim 7, Ding describes that the high refractive index layer comprises one or more layers, and the leaky-wave metasurface is defined therein (“The nanoantennas we used here are metal−insulator−metal (MIM) sandwiched nanobars … A sandwiched nanobar composed of stacked Au, Si, and Au layers, with a thickness of 30 nm for each layer, was placed on top of a 500 nm thick Si slab waveguide on a SiO2 substrate” at 1st complete para. on p. 399, emphasis added).
Regarding claim 8, the Ding – Overvig combination considers that the meta-atoms can be ellipse-shaped (Fig. 2a of Overvig), the magnitude of perturbation is an ellipticity of an ellipse, and the orientation of perturbation is an angular orientation of the ellipse.
Regarding claim 9, the Ding – Overvig combination considers that the meta-atoms can be rectangle-shaped (as illustrated in Fig. 1 of Ding), the magnitude of perturbation is a ratio between the long and short edges of a rectangle, and an orientation of perturbation is an angular orientation of the rectangle (according to the teachings in Figs. 1b and 2a of Overvig).
Regarding claim 13, the teachings of Ding and Overvig combine (see the arguments and motivation for combining, as provided above for claim 1) to teach expressly or render obvious all of the recited step limitations of a corresponding method of using the contemplated integrated metasurface device, as detailed above for claims 1 and 6. Specifically, the Ding – Overvig combination considers a method for converting a waveguide mode (TE00 mode of the single-mode waveguide) into a free-space optical wave (as shown in Fig. 1 of Ding) with a designer wavefront (as described by both Ding and Overvig), comprising:
a) converting the waveguide mode T00 into a slab waveguide mode T00 using a waveguide taper (as illustrated in Fig. 1; “The single-mode waveguide was immediately followed by a taper that could adiabatically convert the fundamental TE00 mode from the single-mode waveguide into a TE00 mode with extended width in the slab waveguide” at the right column on p. 400);
b) coupling the slab waveguide mode into a leaky-wave metasurface the leaky-wave metasurface comprising a plurality of meta-atoms including at least one of dielectric pillars and air apertures etched in the high refractive index layer (as detailed above for claim 1);
c) decomposing the slab waveguide mode within the leaky-wave metasurface into two orthogonal standing waves that are 90-degree out of phase (two orthogonal polarization components which produce a right-hand circularly polarized (RCP) wave and a left-hand circularly polarized (LCP) wave when the relative phase difference between two orthogonal polarization components is ±90 degrees);
d) using two sets of meta-atoms (e.g., ellipse-shaped meta-atoms in Fig. 2a of Overvig) of the leaky-wave metasurface to independently convert the two orthogonal standing waves into two surface emissions with independently controllable amplitude and polarization orientation; and
e) merging the two surface emissions into a single free-space wave (Fig. 2a of Overvig) with completely and independently controllable amplitude, phase, polarization orientation, and polarization ellipticity at each point over the wavefront of the free-space wave (Fig. 4 and its caption; 4th para. on p. 1; para. bridging columns on p. 3; para. bridging pp. 4 – 5 and following para.).
Regarding claim 14, the device of the Ding – Overvig combination does not use non-reciprocal elements, is (inherently) bidirectional, and can be used for either direction of light propagation, i.e., from the waveguide into free-space and/or from free-space into the waveguide. In the latter case, the device of the Ding – Overvig combination implements a method for converting a free-space optical wave with a designer wavefront into a waveguide mode, comprising:
a) decomposing a free-space wave into two free-space components that are 90-degree out of phase;
b) using two sets of meta-atoms of the leaky-wave metasurface to independently convert the two free-space components into two orthogonal standing waves that are within the leaky- wave metasurface comprising a plurality of meta-atoms including at least one of dielectric pillars and air apertures etched in the high refractive index layer (as detailed above for claim 1);
c) combining two orthogonal standing waves into a slab waveguide mode; and
d) coupling the slab waveguide mode into a waveguide mode using a waveguide taper.
Regarding claim 15, Ding describes (Fig. 1; Abstract; pp. 398 – 399) a method of using an integrated metasurface device of claim 1 for free-space wavefront generation, comprising:
a) exciting an integrated metasurface device (comprising nanobars) with a waveguide mode (the TE00 mode of the slab/wide waveguide portion); and
b) establishing a focused beam in free space (“We demonstrated off-chip 2D focusing and holographic projection with our metasurface-dressed photonic integrated devices” in the Abstract).
Regarding claim 16, Ding describes (Fig. 1; Abstract; pp. 398 – 399) a utilization of an integrated metasurface device of claim 1, comprising incorporating the integrated metasurface device into AR/VR displays and wearable devices (“This technology holds the potential for many other optical applications requiring 2D light field manipulation with full on-chip integration, such as solid-state LiDAR and near-eye AR/VR displays” in the Abstract; “the developed platform could be exploited for many other optical applications requiring 2D light field manipulation with full on-chip integration, such as solid-state LiDAR and head-mounted AR/VR displays” at last para. on p. 402).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ROBERT TAVLYKAEV whose telephone number is (571)270-5634. The examiner can normally be reached 10:00 am - 6:00 pm, Monday - Friday.
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/ROBERT TAVLYKAEV/Primary Examiner, Art Unit 2896
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