DETAILED ACTION
This office action is in response to the amendment filed on March 10, 2026. In accordance with this amendment, claims 3, 10, 13, 16, 18, and 19 have been amended, claim 12 has been formally canceled, while new claim 21 has been added. Applicant asserts that independent claim 1 was also “Amended”, but the Examiner is unable to identify any amended features in this claim. If features were intended to be amended into independent claim 1, Applicant may add those features. However, this office action is made FINAL, therefore any further consideration of claim scope (added into independent claim 1) will not be conducted absent the filing of a timely RCE.
Claims 1-11 and 13-21 remain pending, with claims 1, 16, and 19 in independent form. Claims 16-21 would be allowable over the prior art (but-for the non-statutory double patenting rejections), and at least independent claim 1 is finally rejected.
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 .
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries 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 1-4, 6-11, and 13-15 are rejected under 35 U.S.C. 103 as being unpatentable over DeRose et al. U.S. Patent No. 9,759,862 B2, and further in view of Kamei et al. US 2017/0068048 A1 and Lee U.S. Patent No. 5,946,434.
Regarding independent claim 1, DeRose et al. U.S. Patent No. 9,759,862 B2 teaches (ABS; Figs. 1-4, 7; corresponding text, in particular column 3, line 37 through column 6, line 57; Claims) a photonic polarizing beamsplitter (DeRose Figs. 1-4 elements 100 / 200 / 300 / 400), and inherent method for making same (as in claim 1), and the photonic integrated circuit with an input laser source for the beamsplitter (as in claim 19), comprising: a first waveguide 120, a second waveguide 130, and a coupler region 136 that functions with birefringent properties (because the TE and TM modes are coupled differently in this coupling region, birefringence exists when comparing TE and TM coupling through this region) between the first and second waveguides, wherein the coupler is made from a material that is different from the first waveguide (“coupling region 136” can be made from SiO2 as an example, which is different from the waveguides 120 / 140; see column 4, lines 43-51); wherein the beamsplitter separates TE-mode wavelengths and TM-mode wavelengths, the TE-mode wavelengths remaining in the first waveguide and the TM-mode wavelengths being transferred to the second waveguide (see operation of Figs. 1-4; TM transferred to waveguide 130, while TE remains in waveguide 120).
Regarding independent claim 1, the close prior art of DeRose ‘862 teaches birefringent operation (based on the formation of coupling region 136), but this coupling region is not expressly and exactly taught as (1) made “from a birefringent material.” DeRose’s birefringent operation is formed even though SiO2 is not typically referred to in the art as a “birefringent material”. Birefringence in the plain meaning can exist based on the formation of 136 in DeRose, because such region creates different operations for the TE-modes in comparison to the TM-modes (because the TM-modes couple to 130 and the TE-modes are not coupled to 130, expressly based on their polarization). DeRose’s waveguides are formed, with the intervening coupler to function birefringently because the optical features have different effective refractive indices for these different propagation modes (TE and TM).
Further, the close prior art of DeRose ‘862 does not expressly teach that (2) the “second waveguide” comprises “a plurality of outwardly tapering legs with a gap between adjacent legs” and being “connected to a downstream body”, as determined when light is sent/incident on the first waveguide. This missing limitation is found in independent claim 1.
Regarding the first missing limitation, the “birefringent material” being chosen as a suitable material, such as a lithium niobate, or the like, which are birefringent materials, are known in the state of the art of polarization beamsplitters. For example, Lee U.S. Patent No. 5,946,434 teaches (ABS; Figs. 2B; corresponding text; Claims) teaches a polarization beamsplitter using optical materials, and in which birefringent materials are chosen for the features in between two separated optical waveguides 5 and 6. Lee teaches (column 1, lines 15-17; column 2, lines 49-53; column 4, lines 16-19) the use of LiNBO3, or another birefringent semiconductor or polymer material, as the composition to form the photonic polarizing beam splitter on substrate 11. Lee teaches that the advantages of using a birefringent material are for employing low propagation losses with high birefringence, in order to complete mode separation of the TE and TM modes.
Regarding the second missing limitation, in which the second waveguide of claim 1 comprises “a plurality of outwardly tapering legs with a gap between adjacent legs” and being “connected to a downstream body”, Kamei et al. US 2017/0068048 A1 (ABS; Figs. 10, 12, 13, and 14; corresponding text, in particular paragraphs [0120] – [0127]; Claims) a polarization device that uses tapered waveguide legs (at 306, Fig. 14) at the input of one of the waveguides (see Fig. 14), and those tapered waveguide legs are connected to a downstream body 308, in order to efficiently and effectively improve coupling of different modes of optical signals. The prior art of Kamei ‘048 in Figs. 10 and 12-14 teaches that these tapering legs are designed to improve coupling between regions 313 and 314 (Fig. 14) because the tapers minimize loss and also minimize unwanted reflections of the TM and/or TE waves. Also, the tapers (with outward legs) direct signals to a downstream “body” feature of the waveguide at 308. Such tapering in Kamei is used in combination with overlapped levels of operation of the coupling, for example between waveguides at different planar levels of a substrate, or with overlapping waveguide sub-components that cause optical signals to couple in higher/lower propagation paths.
Since DeRose, Lee, and Kamei are all from the same field of endeavor, the purposes disclosed by Lee and Kamei would have been recognized in the pertinent art of DeRose.
A person having ordinary skill in the art at a time before the effective filing date of the current application would have recognized the teachings of Lee and Kamei, to use a birefringent material (such as LiNbO3) for the birefringent coupling region (in claims 1 and 19), and to use the tapering waveguide with a plurality of outwardly tapering legs with a gap therebetween, that is connected to a downstream body, into the base design of the photonic polarizing beamsplitter of DeRose, to allow for the purpose and motivations for each such feature as disclosed in Lee and Kamei. The motivations for using birefringent material for the coupling region, and the motivations for using tapering leg regions with a gap to a downstream body are enumerated in both Lee and Kamei (and noted in the paragraphs above), and would have been recognized by one having ordinary skill in the polarization beamsplitter art at the time of the effective filing of the current application. Further, it would have required no undue burden or unnecessary experimentation to arrive at such features into the base design as found in DeRose Figs. 1-4. See KSR v. Teleflex, 127 S.Ct. 1727 (2007). For these reasons, independent claim 1 is found obvious over DeRose and further in view of Lee and Kamei (henceforth “COMBO”).
Regarding further dependent claims 2-4, 6-11, and 13-15: the overall COMBO features of hypothetical claim 1 must be considered in light of the secondary prior art references of Lee/Kamei. For these reasons, all such dependent claims cited herein are found obvious in view of COMBO and the base independent claim(s). KSR. Many of the base structural features are found in the 1st waveguide - > coupler -> 2nd waveguide formation of DeRose itself, and also Kamei/Lee.
For example, regarding dependent claim 2 (on independent claim 1), Kamei/Lee additionally teaches wherein the plurality of outwardly tapering legs (206a, 206b) has two legs or three legs (see FIG. 10 — there are two legs).
Regarding claim 3, Kamei/Lee additionally teaches wherein the first waveguide (201) or the second waveguide (215, and specifically 206) is formed by a core (first waveguide: 201; second waveguide: 206a-d) surrounded by a cladding (first waveguide: 221, 222; second waveguide: 241, 242; [0125], [0127]; FlGs. 11, 13).
Regarding claim 4, Kamei/Lee additionally teaches wherein the legs (206a, 206b) have a linear taper or a curved taper (see FIG. 10).
Regarding claim 6, Kamei/Lee additionally teaches wherein a distal end of each leg has a width of about 5% to about 95% of a width of the first waveguide; or wherein a proximal end of each leg has a width of about 5% to about 95% of a width of the first waveguide; or wherein each gap has a width of about 5% to about 95% of a width of the first waveguide; or wherein a downstream end of the body has width of about 30 to about 300% of a width of the first waveguide; or wherein the first waveguide (201) has a width of about 0.1 micrometers to about 20 micrometers [0124] discloses that the first waveguide 201 has a width of 0.5 micrometers, which is in such range; or wherein the first waveguide has a length of about 1 micrometer to about 50 micrometers.
Regarding claim 7, Kamei/Lee additionally teaches wherein the second waveguide (215) further comprises a head (“input-output waveguide” 212; [0119]; FIG. 10) downstream of the body (211; see FIG. 10). Kamei/Lee does not explicitly teach that the head is inwardly tapering. However, Kamei teaches many examples throughout of tapered waveguides (e.g., [0119], [0121]-[0122]) and further teaches that tapered waveguides may facilitate adiabatic coupling and mode conversion ([0181)]). Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the instant application, to use a head which is inwardly tapered downstream of the body for the purpose of facilitating adiabatic coupling and mode conversion, thereby rendering obvious instant claim 7 over COMBO. KSR.
Regarding claim 8, Kamei/Lee additionally teaches wherein the head (212) includes a quadrilateral feature. Specifically, [0121] describes head 212 as including a “rectangular core,” which meets the broadest reasonable interpretation of the claim limitation “quadrilateral feature.”
Regarding claim 9, Kamei/Lee additionally teaches wherein a downstream end of the head (rightmost end of 212, not shown in FIG. 10) has a width of about 30% to about 300% of the first waveguide (201; first waveguide 201 and head 212 are consistently described in similar terms, see e.g., [0124], and it follows that a downstream end of the head as a width of about 100% of the first waveguide, which falls within and therefore anticipates the claimed range), and wherein the downstream end width of the head is less than a width of a downstream end of the body (rightmost end of 211; see FIG. 10 — the width of head 212 is consistently less than the width of body 211).
Regarding claims 10, 11, 13, and 14, the overall COMBO features, to include the tapering formation of the form of a Bragg grating, with quadrilateral features of the leg(s) is merely an obvious design choice for the grating / leg configuration to improve optical coupling into a waveguide portion by use of leg(s) being of a preferred shape. KSR.
Regarding claim 15, Kamei/Lee does not explicitly teach that the birefringent coupler (202-205) has an effective refractive index for a TM mode which is greater than a refractive index of the first waveguide (201), and wherein the birefringent coupler has an effective refractive index for a TE mode which is less than the refractive index of the first waveguide. However, Kamei does teach that the effective refractive indices for TM and TE modes in waveguides is dependent on waveguide width (FIGs. 22-23) and further teaches that the devices meet this language.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Each independent claim 1 (and dependent claim 5), 16, and 19 of the current application is rejected on the ground of non-statutory double patenting (NSDP) as being unpatentable over claims 19-20 of Huang et al. U.S. Patent No. 12,050,347 B2. Although the claims at issue are not identical, they are not patentably distinct from each other because independent claim 19 or the ‘347 parent patent teaches: “A method for separating TE-mode wavelengths from TM-mode wavelengths in a photonic device (which implies the device itself), comprising: sending an optical input into a first waveguide, the optical input comprising the TE-mode wavelengths and the TM-mode wavelengths; passing the optical input through a vertical overlap region that includes a birefringent coupler (note no “material”, but such features are implied and in other allowed claims) and a second waveguide above the first waveguide, wherein the second waveguide comprises a plurality of outwardly tapering legs with a gap between adjacent legs that are connected downstream to a body; receiving the TM-mode wavelengths in the second waveguide; and retaining the TE-mode wavelengths in the first waveguide.” Of note is that the vertical overlap feature of ‘347 independent claim 19 meets the amended features into claims 16 and 19 as filed in the current application on March 10, 2026.
Therefore, all features of presented independent claims 1, 16, and 19 are directly found in allowed claim 19 of the parent ‘347 patent, implied therein, or indirectly located in other allowed claims 1-18 (as is dependent claim 5). For these reasons, even though these claims are not identical, Applicant is not permitted to receive a patent on substantially the same subject matter (in independent form) without the filing of a timely terminal disclaimer (TD). Applicant should file a timely terminal disclaimer in response to this office action. Applicant is respectfully requested not to hold such filing in abeyance of an allowance, because all subject matter being prosecuted herein will trigger these non-statutory double patenting rejections. Therefore, even if Applicant places the claims in condition for allowance with amendments around the “Prior Art”, Applicant would nonetheless receive a final rejection under NSDP.
Allowable Subject Matter
Other than the NSDP rejections above to claims 16 and 19 (to the Huang US ‘347 parent patent), these claims would otherwise be found as allowable over the closest prior art rejections in COMBO, above. The express features added to claims 16 and 19 now require all features of “wherein the first waveguide, the birefringent coupler, and the plurality of legs of the second waveguide overlap each other in a vertical overlap region.” Such added feature, in combination, and as arranged, serve to create a patentable distinction over the prior art of COMBO.
Also, noting dependent claim 5, this claim is objected to (based on “Prior Art”), and would make independent claim 1 allowable for the same / similar reasons as claims 16 and 19. However, claim 1 is rejected under both COMBO and NSDP.
Response to Arguments
Applicant’s arguments, see the amendment and arguments regarding dependent claims 10-14, filed March 10, 2026, with respect to the features discussed on pages 6-7, have been fully considered and are persuasive. Therefore, all 35 U.S.C. 112(b) rejections (indefiniteness) as mailed on December 12, 2025 have been withdrawn.
Applicant’s arguments, see the amendment and arguments regarding independent claims 16 and 19, filed March 10, 2026, with respect to the features discussed on pages 9-10, have been fully considered and are persuasive. Therefore, all 35 U.S.C. 103 rejections (obviousness) as mailed on December 12, 2025 to independent claims 16 and 19 (under COMBO) have been withdrawn.
Applicant's arguments filed March 10, 2026 (pages 7-9) regarding the 35 U.S.C. 103 rejections to independent claim 1 to COMBO (see the non-final rejection mailed on December 12, 2025) have been fully considered but they are not persuasive. Respectfully, the Examiner does not agree with the arguments pertaining to the Kamei prior art, or that an overall COMBO, as a whole and as arranged, teaches away from such added features in Kamei. The only feature upon which Kamei was introduced pertains to the ability to increase coupling performance by using tapered features, to a base/body of a waveguide. Therefore, the Examiner respectfully disagrees with this characterization of “teaching away” and the combinability of Kamei with the primary reference to DeRose. Therefore, the rejections of at least independent claim 1 have been made FINAL. The rejections above to claims 1-4, 6-11, and 13-15 meet each requirement for obviousness under 35 U.S.C. 103 based on the tenets of KSR.
However, the Examiner agrees with the amendments into independent claims 16 and 19 to overcome the combination of features in COMBO. Additionally, dependent claim 5 is “objected – to” as including those same features. However, the non-statutory double patenting rejections to each pending independent claim 1, 16, and 19 remain under Huang US ’347.
In response to this office action, and in an effort to advance prosecution to a notice of allowance, the features of dependent claim 5 should canceled and amended into independent claim 1. Further, a timely and proper Terminal Disclaimer (TD) should be filed pertaining to the parent Huang US ‘347 patent.
Inventorship
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.
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 Daniel Petkovsek whose telephone number is (571) 272-4174. The examiner can normally be reached M-F 7:30 - 6 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.
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/DANIEL PETKOVSEK/Primary Examiner, Art Unit 2874 March 27, 2026
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