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 .
Response to Amendment
Applicant’s amendment filed December 5, 2025 has been fully considered and entered.
Drawings
Two (2) sheets of drawings were filed on September 15, 2023.
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 “top cladding” of claims 8 and 9 must be shown or the feature(s) canceled from the claim(s). 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 Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 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)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1, 6, and 7 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Xu et al. (US 2020/0401012 A1; hereafter Xu).
Regarding claim 1; Xu discloses a photonic device (see Figure 2), comprising:
a substrate (chip; see the abstract and title); and
a tantala (tantalum oxide; see claim 5 of Xu) ring resonator (micro-ring resonator; see Figure 2 and claim 5) formed on the substrate (chip) and having at least one of (i) an internal quality factor exceeding three million and (ii) a threshold power for parametric oscillation that is less than 100 mW (see paragraph 58).
Xu does not disclose an internal quality factor exceeding three million. Xu does explicitly disclose all of the claimed structural features of the photonic device of claim 1 as discussed above. The value of the internal quality factor is determined by properties or functions that are presumed to be inherent to the structure of the photonic device. 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). The patentability of a product depends only on the claimed structural limitations of the product. Xu discloses the structural features defined by claim and therefore the claimed properties or functions are presumed to be inherent. The burden is on the applicant to show that the prior art device does not possess the claimed properties or is not capable of these functional characteristics. (See MPEP 2112.01).
The examiner notes that if the claimed structure does not possess the claimed properties or is not capable of performing the claimed functions, 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 internal quality factor exceeding three million is essential.
Regarding claim 6; Xu discloses the substrate being formed of at least one material selected from the group consisting of silicon, thermally oxidized silicon, sapphire, single-crystal quartz, fused silica, gallium arsenide, aluminum gallium arsenide, gallium phosphide, and lithium niobate (see paragraph 10).
Regarding claim 7; Xu discloses the tantala ring resonator having a thickness between 500 nm and 1000 nm (the width cross sectional value, i.e. thickness, is 500 nm for the waveguide structures, wherein the micro-ring is a waveguide structure; see paragraph 55).
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 8 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Xu et al. (US 2020/0401012 A1; hereafter Xu).
Regarding claims 8 and 9; Xu does not disclose a top cladding disposed on the tantala ring resonator, the top cladding being formed of at least one material selected from the group consisting of thermally oxidized silicon, sapphire, single-crystal quartz, and fused silica. The examiner takes official notice that it’s well established in the optical waveguide art that top cladding in the form of silicon dioxide (i.e. oxidized silicon) may be provided over optical waveguides for the purpose of protecting the optical waveguide from damage as well as better confining light within the waveguide. Thus, before the effective filing date of the present invention, a person of ordinary skill in the art would have found it obvious to further provide a top cladding disposed on the tantala ring resonator, the top cladding being formed of at least one material selected from the group consisting of thermally oxidized silicon, sapphire, single-crystal quartz, and fused silica to better confine light within the waveguide and protect the waveguide.
Claims 10, 14, and 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over Xu et al. (US 2020/0401012 A1; hereafter Xu) in view of Wu et al. ("Parametric frequency conversion in Ta2O5 based micro-ring cavity," 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), Munich, Germany, 2017, pp. 1-1, doi: 10.1109/CLEOE-EQEC.2017.8086577.; hereafter Wu) and Kippenberg et al. (US 2018/0083599 A1).
Regarding claim 10, Xu et al. discloses a tantala ring resonator, the tantala ring resonator having at least one of (i) an internal quality factor exceeding three million and (ii) a threshold power for parametric oscillation that is less than 100 mW, but does not disclose a frequency-comb generation method, comprising: sweeping the frequency of a laser having a laser output that is coupled into a tantala ring resonator.
Wu et al. discloses parametric frequency conversion in a tantala (Ta2O5) based micro-ring resonator (see the title and entire disclosure; see Figures 1 and 2). Wu concludes with the statement that “our current results reveal that Ta2O5 has great potentials in developing FWM-based wavelength generation devices”.
Kippenberg teaches that broadband Kerr comb generation relaying on parametric frequency conversation is achievable with high-Q silicon micro-resonators (see paragraph 61). Thus, it’s known in the art to use high-Q micro-resonators in a frequency-comb generation method that includes sweeping the frequency of a laser (see Figure 1 of Knippenberg).
Given the teachings of Wu et al. that tantala micro-ring resonators provide for parametric frequency conversion that may be used in generation devices/methods, and that frequency-comb generation is known to be achieved by sweeping a frequency of a laser having a laser output and coupled to a micro-ring resonator, a person of ordinary skill in the art, before the effective filing date of the present invention, would have found it obvious to use the tantala ring resonator of Xu et al. in a frequency-comb generation method comprising: sweeping the frequency of a laser having a laser output that is coupled into the tantala ring resonator.
Regarding claim 14; Xu teaches the laser output having a power less than 100 mW (see paragraph 58).
Regarding claim 16; Xu teaches the laser output having a power less than 40 mW (see paragraph 58).
Regarding claim 17; Kippenberg teaches (see Figure 1 of Kippenberg) coupling the laser output into the ring resonator (tantala ring resonator as suggested by the teachings of Xu and Wu; see the rejection of claim 10 above).
Regarding claim 18; Xu, Wu, and Kippenberg, teach and/or suggest the frequency-comb generation method of claim 10, as applied, further comprising coupling a Kerr soliton frequency comb out of the tantala ring resonator.
Response to Arguments
Applicant's arguments filed December 5, 2025 have been fully considered but they are not persuasive.
Applicant explains that claim 1 features a tantala resonator formed on a substrate. The tantala resonator further features "at least one of (i) an internal quality factor exceeding three million and (ii) a threshold power for parametric oscillation that is less than 100 mW."
Applicant states that the "internal quality factor" (also referred to as the "unloaded quality factor") quantifies energy loss from a resonator. There are several physical mechanisms that contribute to this energy loss, and therefore lower the internal quality factor. One such mechanism is defects in the crystalline structure of the tantala material. These defects, which are frequently caused by contaminants or voids in the regular periodic arrangement of the atoms forming the crystalline structure, cause light in the resonator to scatter out of the resonator. Other mechanisms that affect the internal quality factor include, but are not limited to, scattering of light off of surface imperfections (e.g., side-wall roughness) and residual absorption of light by the tantala material.
Applicant argues that the inventors have discovered that fabricating tantala photonic structures using ion-beam sputtering leads to fewer defects in the of the tantala, as compared to other thin-film deposition techniques known in the art. What is particularly noteworthy about this discovery is the quantified increase in the internal quality factor. Prior to the present invention, the highest internal quality factor reported for a tantala ring resonator is 182,000 (see C. L. Wu et al., "Efficient wavelength conversion with low operation power in a Ta205-based micro-ring resonator," Optics Letters 42, p. 4804, 2017). This prior-art tantala ring resonator was fabricated using RF sputtering. The tantala resonator reported in the present application has an internal quality factor exceeding 3.2 x 106, which is a factor of -18 higher than the prior-art demonstration.
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., few defects, ion-beam sputtering formation process) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
The examiner notes that ion-beam sputtering is a known method for forming optical devices. For example, Wei (US 6,190,511 B1), which was cited in the Final Rejection of parent application U.S. Patent Application 16/501,134 mailed on April 17, 2023, teaches that Ion beam sputter deposition of thin films including films of tantalum oxide is known formation of optical coatings (see the abstract; col 1 lines 15-25, col 2 lines 39-50, column 4, lines 1-35), wherein the mechanism of ion beam sputtering is described (see column 2, line 5, through column 3, line 10), and wherein Wei teaches that ion beam sputtering of optical films is advantageous in that the resultant films formed using ion beam sputter deposition techniques have high uniformity, high reproducibility, and low contamination (thus lower defects are achieved with ion beam processing of tantalum; see column 2, lines 38-47, which states “Advantages of the above described ion beam sputter deposition (IBSD) include its relatively high uniformity and reproducibility, its relatively strict neutrality, and its relative absence of gaseous contamination. The optical films it produces have both low losses in scattering and in absorption. The refractive indices of thin films are almost as high as corresponding bulk indices. Those of titanium and tantalum oxides are very high,…”), resulting in optical films with low losses to scattering and absorption (see column 2, lines 35-50).
Neither an ion-beam sputtering formation process, nor a range of defects is recited by the claims of the present application. Applicant’s argument that “[t]he inventors have discovered that fabricating tantala photonic structures using ion-beam sputtering leads to fewer defects in the of the tantala” suggests that the fabrication method and range of defects is essential in the present invention. Thus, applicants arguments may be regarded as an implication that the subject matter of claim 1 omits either essential elements (a limitation directed to an acceptable range of defects that provide the claimed functions) and/or essential method steps (a limitation directed to the process essential for obtaining a range of defects that provides the claimed functions) necessary to achieve the claimed invention.
Applicant further states that, thus, the inventors have discovered that by changing the thin-film deposition technique, tantala resonators with substantially higher internal quality factors can be achieved. This increase in quality factor offers many advantages. One key advantage is that the circulating power inside a resonator increases as the internal quality factor increases. This increase in circulating power makes nonlinear optical conversion processes more efficient, and thereby can be used to reduce the amount of power needed to efficiently convert light using one of these processes.
The examiner would like to refer Applicant to the detailed Interview Summary mailed July 29, 2025.
Claim 1 includes two functional limitations ((i) an internal quality factor exceeding three million and (ii) a threshold power for parametric oscillation that is less than 100 mW), wherein the claim only requires one of these functions.
When assessing the functional language, according to MPEP 2173.05(g), there are three factors to consider:
(1) whether there is a clear cut indication of the scope of the claimed subject matter covered by the claim
(2) whether the language sets forth well-defined boundaries of the invention or only states a problem solved or a result obtained
(3) whether one of ordinary skill in the art would know from the claim terms what structure or steps are encompassed by the claim.
With respect to the first factor (1), Examiner Connelly opines that there is not a clear cut indication of the scope of the claimed subject matter covered because claim 1 does not define a specific structure or material property value that allows for the high-Q factor or the threshold power that is claimed, and from the disclosure it's impossible to determine any or all possible scenarios that may have this function, rendering the claim indefinite in view of Applicant’s arguments.
With respect to the second factor (2), Examiner Connelly opines that there are not well-defined boundaries of the invention. The claims simply state a result (Q-factor and/or power threshold) to be obtained.
With respect to the third factor (3), Examiner Connelly opines that one of ordinary skill in the art would not know or understand the structure encompassed by the claim. Regarding this point, the presented arguments indicate that the tantala ring resonator is made with a method that results in lower defects and lower stress, thereby allowing for the high Q-factor. However, the type of method suggested, ion-beam sputtering, is a known method used for forming optical waveguide devices, and there are no claimed details related to the specifics of the method that result in the tantala ring resonator having the lower defects and the lower stress. And more critically, with respect to the claimed device, there are no limitations directed to a defect amount or stress range that provides for the claimed functions.
Applicant summarizes that in the non-final office action dated July 14, 2025, the rejection of claim 1 states: Xu does not disclose an internal quality factor exceeding three million. Xu does explicitly disclose all of the claimed structural features of the photonic device of claim 1 as discussed above. The value of the internal quality factor is determined by properties or functions that are presumed to be inherent to the structure of the photonic device.
Applicant agrees that Xu does not disclose an internal quality factor exceeding three million, and argues that, however, a specific value, or range of values, of the internal quality factor is not necessarily inherent. As discussed above, the internal quality factor can have values that span many orders of magnitude. Accordingly, "an internal quality factor exceeding three million" is an additional structural limitation that is not inherent to the claimed "resonator."
The examiner disagrees. The material structure of a micro-ring resonator necessarily inherently results in a specific value, or range of values of the internal quality factor that is necessarily inherent to the structure.
Applicant’s arguments are stating that the structure is not the same because there is a lower number of defects in the claimed structure. However the claims do not define defects or a range of defects. Thus, Applicant is arguing subject matter that is not claimed.
The prior art, having the same claimed structure, must inherently have the same material properties that that structure will inherently provide. If this is not the case, then there is essential subject matter missing from the claims.
Furthermore, the scope of the claims comes into question, because if the structure providing the claimed functional properties is not clearly defined, then how does one determine what structures are capable of providing the claimed functional properties?
Additionally, ion-beam processes are multiple step process with variables that are also not clearly defined by the claims. Will all ion-beam sputtering processes inherently result in a material that has the same functional properties?
Applicant also states that the office action also alleges that paragraph [0058] of Xu discloses "a threshold power for parametric oscillation that is less than 100 mW." The device discussed in paragraph [0058] is first introduced in paragraph [0056], which states: Example 1 is a silicon MZI-coupled microring for high-efficiency four-wave mixing chip device.
Here Applicant is arguing the limitations of claims 5 and 15, however claims 5 and 15 have been cancelled, so the arguments are moot. In any event, the prior art suggests that a threshold power is within the claimed range and also suggests the use of tantalum to form the resonator.
Applicant concludes that, since Xu does not disclose "an internal quality factor exceeding three million" and "a threshold power for parametric oscillation that is less than 100 mW," Xu does not teach (or suggest) all the limitations of claim 1 and therefore does not anticipate claim 1. Accordingly, we respectfully request reconsideration and withdrawal of the rejection of claim 1.
The examiner disagrees. Xu teaches the claimed structure, and the claimed properties are inherent to the structure. If there is a difference in structure, i.e. a difference in material defects achievable by a different, unobvious process that results in claimed functional properties, then that process and/or range of defects must clearly be recited or defined within both the specification and claims, otherwise there is essential missing subject matter and it is impossible to determine the metes and bounds of the claims.
In the present form, claim 1, in the broadest reasonable interpretation, simply requires a substrate with a tantala micro-ring resonator formed on the substrate. The claimed functions, (i) and (ii) are understood to result from the structure of the device.
Conclusion
THIS ACTION IS MADE FINAL. 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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHELLE R CONNELLY whose telephone number is (571)272-2345. The examiner can normally be reached Monday-Friday, 9 AM to 5 PM.
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, Uyen-Chau Le can be reached at 571-272-2397. 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.
/MICHELLE R CONNELLY/Primary Examiner, Art Unit 2874