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
Claim Objections
Claims 1 – 15 are objected to because of the following informalities:
Claim 1 recites the limitation “the strip of material comprise” which has a typographical error. For the purposes of this Action, the limitation is interpreted as “the strip of material comprises”.
Claim 1 recites the limitation “over the length” in which the article “the” causes an insufficient antecedent basis issue. For the purposes of this Action, the limitation is interpreted as “over a length”.
Claim 4 recites the limitation “the entire length” in which the article “the” causes an insufficient antecedent basis issue. For the purposes of this Action, the limitation is interpreted as “an entire length”.
Claim 6 recites the limitation “the first and second surface” which has a typographical error. For the purposes of this Action, the limitation is interpreted as “the first and second surfaces”.
Claim 11 recites “or.” which has a typesetting issue. For the purposes of this Action, the fragment is interpreted as “or”.
Claim 13 recites the limitation “the second strip of material comprise” which has a typographical error. For the purposes of this Action, the limitation is interpreted as “the second strip of material comprises”.
Appropriate corrections are required.
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, 2, 4, 6 – 8, and 10 – 15 are rejected under 35 U.S.C. 103 as being unpatentable over Thompson et al (US 2023/0152611 A1) in view of Wessels et al (US 7,224,878 B1).
Regarding claims 1 and 2, Thompson discloses (Figs. 6 and 10; para. 0033, 0037, 0043, 0048, and 0049) a phase actuator/shifter/modulator comprising (with reference to Fig. 6):
an optical waveguide (defined by a silicon nitride core 250 (and an optional core 252) and a cladding formed by an adjacent portion of a layer 210,212 (para. 0037 and 0047)) wherein the optical waveguide comprises at least one strip 250,252 of silicon nitride (para. 0043) embedded in a layer 210,212 of silicon dioxide (SiO2; para. 0035 and 0047) (as shown in Fig. 6);
a strip of material 206 on or in the optical waveguide (defined by 250,252,210,212) wherein the strip of material 206 comprises a material (e.g., Barium Titanate; para. 0033) that is electro-optically active and acts as an electro-optical modulator (para. 0026);
a signal electrode (one of 230 and 232 which corresponds to the electrode to which voltage V0 is applied in Fig. 1) in contact with a first (top) surface of the strip of material 206; and
a ground electrode (the other one of 230 and 232 which corresponds to the grounded electrode in Fig. 1) separated from the signal electrode (as seen in Fig. 6).
Thompson does not expressly teach that the modulator can be configured to provide high-speed modulation by employing traveling-wave electrodes, even though such type is well known in the art. For example, Wessels discloses (Figs. 5, 8, 9, and 11; 6:5 – 7; 6:65 – 9:15) an electro-optic phase modulator having essential structural features similar to those in Thompson and comprising:
an optical waveguide wherein the optical waveguide comprises at least one strip of silicon nitride (Si3N4) embedded in a layer 210 of silicon dioxide (SiO2) (as shown in Figs. 5 and 9); and
a strip of material (BaTiO3 which is the same material as that cited by Thompson),
wherein the strip of material comprises a material that is electro-optically active and acts as an electro-optical modulator.
Wessels expressly teaches that the modulator further comprises a pair of traveling-wave electrodes (of the CPS type) comprising a signal electrode and a ground electrode that are configured allow a travelling electro-magnetic wave to propagate over a length of the phase actuator (“A thin film composite structure of BaTiO.sub.3/MgO has been shown to lower the effective microwave index enabling velocity match between the microwave and optical waves needed for high-speed traveling wave operation” at 1:44 – 49, emphasis added).
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 electrodes in Thompson can be configured, in accordance with the teachings of Wessels, to be travelling-wave electrodes (e.g., of the CPS type) in order to enable high-speed modulation (with frequencies up to tens of GHz; e.g., “a 5 mm-long electrode would result in an optical 3-dB bandwidth greater than 40 GHz BaTiO.sub.3 thin film modulator” at 9:12 – 14 of Wessels).
Regarding claims 6, 7, and 10, the Thompson – Wessels combination considers (Fig. 6 of Thompson) that the strip of material 206 (Barium Titanate) is on a surface of the optical waveguide (defined by the silicon nitride core 250 (and the optional core 252) and the cladding formed by an adjacent portion of the layer 210,212) such that a second (bottom) surface of the strip of material 206 interfaces with the optical waveguide, wherein the first (top) surface and second (bottom) surface of the strip of material 206 are opposing surfaces, and wherein the surface of the optical waveguide comprises a surface of the layer 210,212 of silicon dioxide (as seen in Fig. 6). The Thompson – Wessels combination considers embodiments wherein the signal electrode and the ground electrode can be disposed on either the first (top) surface (as in Fig. 6 of Thompson, for modulation with a horizontal component of the electrical field) or the second (bottom) surface (as in Fig. 8, for modulation with a horizontal component of the electrical field), or both top and bottom surfaces (according to Fig. 11, for modulation with a vertical component of the electric field). In the latter two alternative choices, the ground electrode is in contract with a second surface of the strip of material (Barium Titanate), wherein the first (upper) surface and second (bottom) surface of the strip of material are opposing surfaces.
Regarding claim 8, the Thompson – Wessels combination considers (Fig. 6 of Thompson) that the surface of the optical waveguide (defined by the silicon nitride core 250 (and the optional core 252) and the cladding formed by an adjacent portion of the layer 210,212) comprises at least a surface of one of the at least one strips of silicon nitride 250,252 (defining the waveguide core); and optionally the surface of the optical waveguide extends to include a surface of the layer of silicon dioxide 210,212 (defining the waveguide cladding).
Regarding claim 11, the Thompson – Wessels combination considers (Fig. 6 of Thompson) that either:
the ground electrode (one of 230 and 232), strip of material 206, and signal electrode (the other of 230 and 232) are embedded in the layer of silicon dioxide 210,212.
Regarding claim 12, the Thompson – Wessels combination considers (Fig. 6 of Thompson) that the signal electrode (one of 230 and 232), the strip of material (its ridge part 251) and the ground electrode (the other of 230 and 232) extend along only (upper) part 212 of the layer of silicon dioxide 210,212.
Regarding claims 4 and 13, Fig. 1 of Thompson shows that the disclosed phase modulator can be comprised in a Mach-Zehnder interferometer (para. 0027). Thompson teaches that “Although a single active arm is illustrated in FIG. 1, it will be appreciated that both arms of the Mach-Zehnder interferometer can include phase adjustment sections” (para. 0028, emphasis added). Hence, Thompson renders obvious a Mach-Zehnder modulator embodiment wherein:
the strip of (electro-optic) material comprises a first strip of material (a first rib/strip 251 in one interferometer arm), and
a second strip of (electro-optic) material (a second rib/strip 251 in the other interferometer arm) wherein the second strip of material comprises an electro-optical (phase) modulator.
The pair of phase modulators in the two interferometer arms have the same structural features and are driven by separate voltages. Thompson renders obvious that the pair of phase modulators can share a common slab layer 206 or have separated slab layers 206. In the latter case, a second signal electrode in contract with a first surface of the second strip of material; wherein the first strip of material is embedded in the layer of silicon dioxide on a first (e.g., left) side of the at least one strip of silicon nitride (two silicon nitride strips making up the two interferometer arms; the second strip of material is embedded in the layer of silicon dioxide on a second (right) side of the at least one strip of silicon nitride wherein the first side and the second side of the at least one strip of silicon nitride are opposite (left and right) sides of the at least one strip of silicon nitride.
Further for claim 4, in a Mach-Zehnder interferometer considered by Thompson, each interferometer arm comprises a corresponding strip of electro-optic material and a corresponding waveguide core defined by a silicon nitride strip so that the at least one strip of silicon nitride comprises a first (left) strip 250 and second (right) strip 250 of silicon nitride embedded in the layer of silicon dioxide 210,212; the first and second strip of silicon nitride are of the same length (equal interferometer arms) as each other and do not extend across the entire length of the layer of silicon dioxide (interferometer arms are shorter than the entire length of the Mach-Zehnder interferometer which comprise input/output waveguide and 2x2 couplers, as seen in Fig. 1 of Thompson); the first and second strip of silicon nitride are separated from each other by the layer of silicon dioxide 210,212 and are aligned with each other (according to Fig. 1).
Regarding claim 14, as detailed above for claims 13 and 6, the Thompson – Wessels combination considers that each interferometer arm comprises a corresponding strip of electro-optic material and is driven (phase modulated) separately by a corresponding pair of electrodes, which may be disposed on the top surface, the bottom surface or both surfaces of the two strips of (electro-optic) material (to modulate both interferometer arms), as detailed above for claim 6. In this case, the ground electrode is a first ground electrode; the first ground electrode is in contact with a second surface of the first strip of material, wherein the first surface and second surface of the strip of material are opposing surfaces; and that the phase actuator further comprises: a second ground electrode wherein the second ground electrode is in contact with a second surface of the second strip of material, wherein the first surface and second surface of the strip of material are opposing surfaces.
Regarding claim 15, the Thompson – Wessels combination considers that the ground electrode is in contact with a surface of the silicon dioxide layer, as detailed above for claims 1 and 13.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Thompson in view of Wessels, and further in view of “Low-Loss Si3N4 TriPleX Optical Waveguides: Technology and Applications Overview” by Roeloffzen et al, IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, vol. 24, No. 4, paper 4400321, 2018 (hereinafter Roeloffzen).
Regarding claim 3, Thompson does not teach that the described waveguide can be formed by a TriPlex technology and be a TriPlex waveguide. However, Roeloffzen describes (Figs. 1 and 2; Abstract; Sections I and II) a family of TriPlex waveguides. 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 of the Thompson – Wessels combination can be a TriPlex waveguide which has the benefits of low optical loss and suitability for hybrid integration (Abstract of Roeloffzen).
Claims 4 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Thompson in view of Wessels, and further in view of Shi et al (US 2023/0055077 A1).
Regarding claim 4, Fig. 6 of Thompson illustrates, by way of example but not limitation, the waveguide core 250 formed as a single strip of silicon nitride and Thompson does not teach a waveguide core formed by two or more vertically-stacked strips of silicon nitride. However, Shi discloses (Fig. 1A; Abstract; para. 0050 – 0055) an electro-optic phase modulator having essential structural features similar to those in Thompson and comprising:
an optical waveguide wherein the optical waveguide comprises at least two vertically-stacked and evanescently-coupled strips of silicon nitride 130,110 embedded in a layer 123,127 of silicon dioxide (para. 0051, 0053); and
a strip of material 135 (lithium niobate), wherein the strip of material comprises a material that is electro-optically active and acts as an electro-optical modulator (Abstract).
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 core in Thompson can comprise, in accordance with the teachings of Shi, two vertically-stacked and evanescently-coupled strips of silicon nitride. Such arrangement may be used for shaping/tailoring a mode profile of a composite core (comprising two sub-cores) and/or for evanescently coupling input and output waveguides to the electro-optic modulator (para. 0053 of Shi).
Regarding claim 9, the Thompson – Wessels – Shi combination considers that the lower portion of the layer of silicon dioxide comprises two layers (123 and 127 in Fig. 1A of Shi) comprises so that there is a second layer of silicon dioxide on the second (bottom) surface of the strip of (electro-optic) material.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Thompson in view of Wessels, and further in view of “Preferential growth of perovskite BaTiO3 thin
films on Gd3Ga5O12(100) and Y3Fe5O12(100) oriented substrates by pulsed laser deposition” by Ruf et al, Mater. Adv., vol. 3, pp. 4920–4931, 2022 (hereinafter Ruf).
Regarding claim 5, Thompson teaches (Fig. 6) a bonding (seed) layer 204 between the optical waveguide 250,210 and the strip of material 206 (barium titanate (BaTiO3)). Thompson cites, by way of example but not limitation, that the bonding (seed) layer 204 can comprise MgO (para. 0034, 0038, and 0039), but does not list other suitable/workable material choices. However, Ruf describes (Abstract; Sections ‘Introduction” and “Conclusions”) BaTiO3 thin films grown on Gd3Ga5O12 and Y3Fe5O12. 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 bonding (seed) layer 204 in Thompson can alternatively be formed from Gd3Ga5O12 or Y3Fe5O12., as alternative material choices that are described by Ruf and enable high-quality BaTiO3 films (“a better crystallinity of the BTO thin film, as achieved on a GGG(100) or YIG(100) substrate, could be sufficient for improving device qualities” in the Conclusions of Ruf).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 2006/0222281 A1
US 2023/0234310 A1
US 2023/0152608 A1
“The Silicon-Based XOI Wafer: The Most General Electronics-Photonics Platform for Computing, Sensing, and Communications” by Soref et al, IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, vol. 29, No. 2, paper 8200108, 2023 (online publication 10/3/2022).
“216 GBd Plasmonic Ferroelectric Modulator Monolithically Integrated on Silicon Nitride” by Kohli et al, European Conference on Optical Communication, paper Tu4E.5, 2022.
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.
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, William Kraig can be reached on (571)272-8660. 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.
/ROBERT TAVLYKAEV/Primary Examiner, Art Unit 2896