Detailed Office 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 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.
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 1-14
Claims 1-14 are rejected under 35 U.S.C. 103 as being unpatentable over Walker et al. (The Design of 50 GHz Gallium Arsenide Electro-Optic Modulator Arrays for Satellite Communications Systems, Frontiers in Physics, Volume 9 – 2021 (February); “Walker”) in view of Ozaki et al. (JP 2014114343 A; “Ozaki”), further in view of Dogru et al. (0.77-V drive voltage electro-optic modulator with bandwidth exceeding 67 GHz, Opt. Lett. 39, 6074-6077 (2014); “Dogru”), and further in view of Shin et al. (Conductor Loss of Capacitively Loaded Slow Wave Electrodes for High-Speed Photonic Devices. Lightwave Technology, Journal of. 29. 48 – 52, 2011; “Shin”).
Claims 2-14 depend upon claim 1.
Regarding claim 1, Walker discloses in figures 1 and 3, and related figures and text, for example, Walker – Selected Text, traveling wave electro-optic modulator embodiments “traveling wave modulator” comprising: a substrate “Si GaAs Substrate; first and second parallel spaced apart electrode strips arranged on the substrate (disclosed as connected to “Matched Termination”); first and second optical waveguides “Waveguide ridges” (disclosed as connected to “Split” and “Recombine”) arranged on the substrate, the optical waveguides being positioned between the first and second electrode strips “Thin metal electrodes” and extending parallel thereto; the first electrode strip comprising at least one portion (disclosed as “Segmented” T rail) extending proximate to the first optical waveguide; the second electrode strip comprising at least one portion extending proximate to the second optical waveguide; a third electrode strip parallel to the first and second electrode strips (disclosed as laterally disposed to the first and second electrode strips and connected to the first and second electrode strips at “Matcher Termination”);a semiconductive backplane layer “AlGaAs Lower Claddings (n+ Doped Backplane) arranged within the substrate and extending between the waveguides; and, a matched termination “Matched Termination” connected to the first and second electrode strips.
Walker – Figures 1 and 3
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Walker – Selected Text
Modulator Design.
The Mach-Zehnder modulator (Figure 1) consists of a parallel pair of electro-optic phase modulator waveguides, fed by an optical splitter, differentially driven and finally recombined to the device output. The phase modulators use the vertical E-field between the top Schottky electrode and a set of doped backplane layers grown into the epitaxy beneath the waveguides. The E-field (utilizing the linear electro-optic effect) has a high overlap with the guided optical profile confined by the GaAs/AlGaAs refractive-index contrast vertically and by the etched rib horizontally.
Since the phase-modulators are inherently connected back-to-back by the doped backplane, they naturally operate in a series push-pull mode [5, 6]. The applied RF potential divides equally between the waveguides, producing balanced, anti-phase contributions to the modulation, and with an effective capacitance which is half that of the individual branches.
The capacitively loaded line is a slow-wave structure in which the modulation electrodes are segmented as a set of short quasi-lumped elements isolated by passive spaces….
The loading capacitance is derived from the epitaxial sheet capacitance, the waveguide geometry and the fill-factor of the segmentation – typically high at nearly 100%. The passive spaces reduce length efficiency, so are minimized. Capacitance is optimized via the epitaxial specification and/or waveguide width, with less direct impact on Vπ than by reducing the fill factor….
Further regarding claim 1, Walker does not explicitly disclose serpentine conductive strips.
However, Ozaki discloses in figure 7, and related figures and text, embodiments of conductive strips 205 and 207 connecting signal source 211 with common terminator (shown but not labeled), strip 205 having serpentine section 406 and strip 207 having serpentine section 408.
Ozaki – Figure 7
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Consequently, it would have been obvious to one of ordinary skill in the art to modify Walker’s embodiments to disclose a serpentine electrically conductive strip arranged on the substrate and connecting the first and second electrode strips together because the resultant configuration would facilitate realizing impedance and velocity matching. Ozaki, Description of the Embodiments.
Further regarding claim 1, Walker in view of Ozaki does not explicitly disclose that the backplane matching element comprises a plurality of semiconductive backplane plates connected together by at least one semiconductive backplane arm, the plates and at least one backplane arm being arranged within the substrate, the plates being arranged proximate to the electrode strips such that each electrode strip is capacitively coupled to at least one backplane plate; the serpentine electrically conductive strip being arranged such that at least a portion of its length is proximate to at least one backplane arm such that the two are electrically coupled together.
However, Dogru discloses in figure 3, and related figures and text, Mach-Zehnder embodiments having electrode segments characterized by vertical coupling between T-shaped signal segments and T-shaped ground segments.
Dogru – Figure 3
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Consequently, in light of Dogru’s segmented ground and signal electrodes, it would have been obvious to one of ordinary skill in the art to modify Walker in view of Ozaki’s embodiments to explicitly disclose that the backplane matching element comprises a plurality of semiconductive backplane plates connected together by at least one semiconductive backplane arm, the plates and at least one backplane arm being arranged within the substrate, the plates being arranged proximate to the electrode strips such that each electrode strip is capacitively coupled to at least one backplane plate; the serpentine electrically conductive strip being arranged such that at least a portion of its length is proximate to at least one backplane arm such that the two are electrically coupled together; because the resultant embodiments’ abilities to configure T-rails would facilitate adjusting backplane conductance. Shin, figure 1, and related figure and text, for example abstract (“the proposed approach enables complete design of capacitively loaded slow wave electrodes by predicting the microwave loss with closed-form equations in addition to velocity and characteristic impedance.”).
Shin – Figure 1
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Regarding dependent claims 2-14, it would have been obvious to one of ordinary skill in the art to modify Walker in view of Ozaki, further in view of Dogru, and further in view of Shin’s embodiments, as applied in the rejection of claim 1, to disclose:
2. The travelling wave electro-optic modulator as claimed in claim 1, wherein for at least one of the first and second electrodes the at least one portion is a T rail. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
3. The travelling wave electro-optic modulator as claimed in claim 1, wherein the serpentine strip is a metal strip. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
4. The travelling wave electro-optic modulator as claimed in claim 1, further comprising a third electrode strip parallel to the first and second electrode strips. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
5. The travelling wave electro-optic modulator as claimed in claim 4, wherein the matched termination is further connected to the third electrode strip with the serpentine strip connecting the first, second and third electrode strips together. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
6. The travelling wave electro-optic modulator as claimed in claim 1, wherein the serpentine electrically conductive strip and backplane matching element are arranged in parallel spaced apart planes. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
7. The travelling wave electro-optic modulator as claimed in claim 6, wherein when viewed along a direction normal to the parallel spaced apart planes the serpentine electrically conductive strip and backplane matching element at least partially overlap. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
8. The travelling wave electro-optic modulator as claimed in claim 7, wherein each backplane arm is U shaped, at least a portion of the U overlapping with the serpentine electrically conductive strip when viewed along the direction normal to the parallel spaced apart planes. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
9. The travelling wave electro-optic modulator as claimed in claim 7, wherein at least one backplane arm comprises a backplane spur portion, at least a portion of the backplane spur portion overlapping with the serpentine electrically conductive strip when viewed along the direction normal to the parallel spaced apart planes. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
10. The travelling wave electro-optic modulator as claimed in claim 7, wherein the serpentine electrically conductive strip comprises a plurality of substantially parallel straight portions connected together by U shaped portions, at least some of the straight portions and U shaped portions overlapping the backplane matching element when viewed along the direction normal to the parallel spaced apart planes. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
11. The travelling wave electro-optic modulator as claimed in claim 1, wherein the serpentine electrically conductive strip and backplane matching element are configured such that the slope of the RF reflection coefficient as a function of frequency for one is substantially equal and opposite to that of the other at the point of crossover of the two. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
12. The travelling wave electro-optic modulator as claimed in claim 1, further comprising an optical source connected to the optical waveguides. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
13. The travelling wave electro-optic modulator as claimed in claim 1, further comprising an RF source connected to the first, second and central electrode strips. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
14. The travelling wave electro-optic modulator as claimed in claim 1, wherein the backplane matching element comprises an n doped AlGaAs portion arranged within the substrate. Walker, figures 1 and 3, and related figures and text, for example, Walker – Selected Text; Ozaki discloses in figure 7, and related figures and text; Dogru, figure 3, and related figures and text; Shin, figure 1, and related figure and text.
because the resultant configurations would facilitate realizing impedance and velocity matching; Ozaki, Description of the Embodiments, by tailoring electrodes shapes to adjust backplane conductance. Shin, figure 1, and related figure and text, for example abstract (“the proposed approach enables complete design of capacitively loaded slow wave electrodes by predicting the microwave loss with closed-form equations in addition to velocity and characteristic impedance.”).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PETER RADKOWSKI whose telephone number is (571)270-1613. The examiner can normally be reached on M-Th 9-5. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Thomas Hollweg, can be reached on (571) 270-1739. The fax phone number for the organization where this application or proceeding is assigned is (571) 273-8300.
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/PETER RADKOWSKI/Primary Examiner, Art Unit 2874