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 1-8
Claims 1-8 are rejected under 35 U.S.C. 103 as being unpatentable over Ozaki et al. (High-speed Modulator for Next-generation Large-capacity Coherent Optical Networks, NTT Technical Review, Vol. 16, No. 4, pp. 49–56, Apr. 2018.; “Ozaki”) in view of Ishimura (2012/0087614; “Ishimura”) and further in view of Patel et al. (Frequency response of dual-drive silicon photonic modulators with coupling between electrodes, Vol. 26, No. 7 | 2 Apr 2018 | OPTICS EXPRESS 8904; “Patel”).
Regarding claim 1, Ozaki discloses in figure 9, and related figures and text, embodiments of differentially driven IQ modulators co-assembled with Integrated Circuit (IC) drivers. See Ozaki, figure 9, and related figures and text.
Ozaki – Figure 9
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Further regarding claim 1, Ishimura discloses in figures 1 and 13-16, and related figures and text, for example, Selected Text, embodiments of optical modulators disclosing a wires connecting signal S to the pad of a signal electrode ‘acting’ on one arm of two arms of a MZ modulator, figures 1 and 13-16, and embodiments in which the signal source sandwiched between grounds G – with no wires attaching the Gs to ground electrodes (figures 13-16).Ishimura, figures 1 and 13-16, and related figures and text, for example, Selected Text.
Ishimura – Figures 1 and 13-16, and Selected Text
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Abstract. An optical modulator includes: a semiconductor chip; a waveguide in the semiconductor chip; a traveling wave electrode including an input portion and an output portion, to which a signal is applied for modulating light passing through the waveguide; a power supply line connected to the input portion via a first wire; and a termination resistor connected to the output portion via a second wire. Capacitance between the output portion and a grounding point is larger than capacitance between the input portion and the grounding point.
[0030] A ground line 28 is formed on each side of the power supply line 20, and a ground line 30 is formed on each side of the terminating line 24. The ground line 28 is connected to the input side of the ground line 16 via a wire 32, and the ground line 30 is connected to the output side of the ground line 16 via a wire 34.
[0031] The area of the bonding pad of the output portion 14b is larger than the area of the bonding pad of the input portion 14a. Therefore, the electric capacity between the output portion 14b and the grounding point is larger than the electric capacity between the input portion 14a and the grounding point. In the same manner, a traveling wave electrode, a ground line, a power supply line, a terminating resistor, and the like are formed in the arm 12b side.
[0054] FIG. 15 is a top view showing a modified example of an optical modulator according to the fifth embodiment. The width of the waveguide 12 can be widened from the input side toward the output side to meet the change in the width of the
[0055] FIG. 16 is a top view showing an optical modulator according to the sixth embodiment. First and second insulating films 52 and 54 are formed on the semiconductor chip 10. The input portion 14a of the traveling wave electrode 14 is formed on the first insulating film 52, and the output portion 14b is formed on the second insulating film 54. The second insulating film 54 is thinner than the first insulating film 52, and is about one-third. Thereby, the electric capacity between the output portion 14b and the grounding point is about 0.2 pF higher than the electric capacity between the input portion 14a and the grounding point. As a result, in the same manner as in the first embodiment, the modulation bandwidth can be sufficiently expanded.
[0052] FIG. 13 is a top view showing an optical modulator according to the fourth embodiment. The traveling wave electrode 14 is not the GSG electrode as in the first embodiment. The area of the bonding pad on the output portion 14b is three-times the area of the bonding pad on the input portion 14a. Thereby, the electric capacity between the output portion 14b and the grounding point is about 0.2 pF higher than the electric capacity between the input portion 14a and the grounding point. As a result, in the same manner as in the first embodiment, the modulation bandwidth can be sufficiently expanded. The electric capacity can be also elevated by connecting the output portion 14b to the p-n joint of the semiconductor chip 10.
[0054] FIG. 15 is a top view showing a modified example of an optical modulator according to the fifth embodiment. The width of the waveguide 12 can be widened from the input side toward the output side to meet the change in the width of the traveling wave electrode 14.
[0055] FIG. 16 is a top view showing an optical modulator according to the sixth embodiment. First and second insulating films 52 and 54 are formed on the semiconductor chip 10. The input portion 14a of the traveling wave electrode 14 is formed on the first insulating film 52, and the output portion 14b is formed on the second insulating film 54. The second insulating film 54 is thinner than the first insulating film 52, and is about one-third. Thereby, the electric capacity between the output portion 14b and the grounding point is about 0.2 pF higher than the electric capacity between the input portion 14a and the grounding point. As a result, in the same manner as in the first embodiment, the modulation bandwidth can be sufficiently expanded.
In light of Ishimura’s wire bonding embodiments, it would have been obvious to one of ordinary skill in the art to modify Ozaki’s differentially driven IQ embodiments to disclose an IQ modulator comprising at least two or more Mach-Zehnder modulators; and a differential driver IC connected to the IQ modulator, wherein each of the at least two or more Mach-Zehnder modulators comprises a differential transmission line, the differential transmission line comprises two signal lines for transmitting high-frequency modulated signals including differential signals, the differential transmission line includes a PAD portion for connection with another element, a lead line portion, a phase modulation portion, and a termination portion, and the other element includes the differential driver IC, the PAD portion includes a set of four first metal PADs having a GSSG configuration or a set of five first metal PADs having a GSGSG configuration, in which G is Ground and S is Signal, and the lead line portion, the phase modulation portion, and the termination portion have an SS line configuration; Ozaki, figure 9, and related figures and text; Patel, figures 1 and 2, and related figures and text; Ishimura, figures 1 and 13-15, and related figures and text, for example, Selected Text; because the resulting configurations and methods would facilitate designing, fabricating, and deploying GSSG-based IQ modulators with waveguides symmetrically sandwiched between two signal electrodes. Patel, figures 1 and 2, and related figures and text.
Patel – Figures 1 and 2, and Selected Text
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Abstract: We characterize the electro-optic frequency response of a four-port traveling-wave dual-drive modulator with relatively strong coupling amongst the electrodes. We show that the electro-optic frequency response of the MZM can still be predicted with the 2×2 cascaded matrix model if the MZM is symmetric and differentially driven.
With dual-drive modulators, even if two pn junctions are placed in series between the two signal electrodes, the effective resistance and capacitance is that of a single pn junction. This happens because the MZM is driven differentially (odd mode), which means the negative electrode has the same magnitude but opposite polarity to that of the positive electrode. Additionally, because of physical symmetry, the potential at the middle represents a 0 V. The electric fields are also parallel at the middle emulating an electrical conductor wall. Hence, a virtual ground is present at the middle of the line and the equivalent junction resistance and capacitance seen by the unloaded transmission line is that of a single pn junction Rmod = Rpn and Cmod = Cpn. Here, Rpn and Cpn are in lumped units and represents the portion of a segment that is loaded by the pn junction (λloaded). The input RF pads and transition, which take the signal from the point of application to the beginning of the uniform transmission line, as shown in Fig. 2(a), can be represented by another ABCD matrix converted from the S-parameter response of the pads and transition. The overall transmission matrix can then be represented as…as illustrated in Fig. 2(b)…
Regarding claims 2-8, it would have been obvious to one of ordinary skill in the art to modify Ozaki in view of Ishimura and further in view of Patel, as applied in the rejection of claim 1, to disclose:
2. The driver integrated IQ optical modulator according to claim 1, wherein the differential driver IC includes a set of four second metal PADs with a GSSG configuration or a set of five second metal PADs with a GSGSG configuration, and the set of four second metal PADs or the set of five second metal PADs are connected by wires to the corresponding set of four first metal PADs or the set of five first metal PADs. Ozaki, figure 9, and related figures and text; Patel, figures 1 and 2, and related figures and text; Ishimura, figures 1 and 13-15, and related figures and text, for example, Selected Text.
3. The driver integrated IQ optical modulator according to claim 2, wherein a wire connecting the second metal PAD provided in the differential driver IC and the first metal PAD provided in the IQ modulator is configured through ball bonding, each configuration between the first metal PAD and the second metal PAD associated with Signal in the GSSG configuration or the GSGSG configuration is connected to a set of four wires, a pair of a first wire and a second wire of the set of four wires has substantially the same path in top view and different paths in side view, a pair of a third wire and a fourth wire in the set of four wires has substantially the same path in top view and different paths in side view, and a pair of the first wire and the third wire of the set of four wires has different paths in top view and substantially the same path in side view. Ozaki, figure 9, and related figures and text; Patel, figures 1 and 2, and related figures and text; Ishimura, figures 1 and 13-15, and related figures and text, for example, Selected Text.
4. The driver integrated IQ optical modulator according to claim 2, wherein, in at least one of the set of the second metal PADs provided in the differential driver IC and the set of the first metal PADs provided in the IQ modulator, a wire is connected between the first metal PADs or between the second metal PADs related to Ground in the GSSG configuration or the GSGSG configuration, and the wire connecting between the first metal PAD or between the second metal PAD associated with the Ground is configured to surround a wire connecting between the first metal PAD and the second metal PAD associated with Signal of the GSSG configuration or the GSGSG configuration. Ozaki, figure 9, and related figures and text; Patel, figures 1 and 2, and related figures and text; Ishimura, figures 1 and 13-15, and related figures and text, for example, Selected Text.
5. The driver integrated IQ optical modulator according to claim 2, wherein the first metal PAD associated with Ground closest to the periphery of the IQ modulator of the set of the first metal PADs having the GSSG configuration provided in the IQ modulator or the set of the first metal PADs having the GSGSG configuration is connected to an external ground potential. Ozaki, figure 9, and related figures and text; Patel, figures 1 and 2, and related figures and text; Ishimura, figures 1 and 13-15, and related figures and text, for example, Selected Text.
6. The driver integrated IQ optical modulator according to claim 5, wherein each of the at least two or more Mach-Zehnder modulators includes the phase modulation portion has a capacitance loading structure, and the impedance of the capacitance loading structure is 3% or more higher than the impedance of a terminal resistor provided in the termination portion. Ozaki, figure 9, and related figures and text; Patel, figures 1 and 2, and related figures and text; Ishimura, figures 1 and 13-15, and related figures and text, for example, Selected Text.
7. The driver integrated IQ optical modulator according to claim 2, wherein the set of the second metal PADs provided in the differential driver IC is installed at a higher position than the set of the first metal PADs provided in the IQ modulator. Ozaki, figure 9, and related figures and text; Patel, figures 1 and 2, and related figures and text; Ishimura, figures 1 and 13-15, and related figures and text, for example, Selected Text.
8. The driver integrated IQ optical modulator according to claim 1, wherein the Mach-Zehnder modulator includes a semiconductor substrate, a waveguide structure formed on the semiconductor substrate, and a layer formed on the semiconductor substrate using a low dielectric material to embed the waveguide structure, and the set of first metal PADs is formed on a layer formed using the low dielectric material. Ozaki, figure 9, and related figures and text; Patel, figures 1 and 2, and related figures and text; Ishimura, figures 1 and 13-15, and related figures and text, for example, Selected Text.
because the resulting configurations and methods would facilitate designing, fabricating, and deploying GSSG-based IQ modulators with waveguides symmetrically sandwiched between two signal electrodes. Patel, figures 1 and 2, and related figures and text
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 M-Th 9-5.
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/PETER RADKOWSKI/Primary Examiner, Art Unit 2874
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