DETAILED ACTION
Claim Rejections - 35 USC § 102
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)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1, 2, 4, 8-12, 14, 15, 17 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by U.S. PGPub 202/0373828 A1 by Yoshida et al.
Regarding claim 1, Yoshida teaches an optical modulator (Figs. 2-6) comprising: an electro-optic layer (PZT waveguide 31 of a PZT thin film 55) including an electro-optic material (PZT); a material layer (first cladding 54) arranged below the electro-optic layer and having a dielectric constant lower than a dielectric constant of the electro-optic layer (by way of TiO2 or SiO2); a core layer (Si waveguide 21) arranged below the material layer and having a refractive index higher than refractive indices of the electro-optic layer and the material layer (nSi>nTiO2, nSiO2, or nPZT); and an electrode (32) that applies an electric signal to the electro-optic layer, wherein the refractive index of the material layer is 0.85 times the refractive index of the electro-optic layer or higher (nTiO2>nPZT).
Regarding claim 2, Yoshida the electro-optic layer has an electro-optic coefficient higher than an electro-optic coefficient of the material layer (PZT is a high EO coefficient material compared to conventional EO materials such as LiNbO3 as noted by applicant, whereas TiO2 is used as a cladding layer in the modulator).
Regarding claim 4, Yoshida teaches the electro-optic layer includes PbZrTiO3 (PZT).
Regarding claim 8, Yoshida further teaches a cladding layer (56) arranged on at least part of the electro-optic layer, the part being on the core layer, wherein the cladding layer has a relative dielectric constant of 15 or less and a refractive index of 1.8 or less (SiO2, ¶[0066]).
Regarding claim 9, Yoshida further teaches a cladding layer (56) arranged on at least part of the electro-optic layer, the part being on the core layer, wherein the cladding layer includes SiO2 (¶[0066]).
Regarding claim 10, Yoshida further teaches a first material layer (56) arranged between the electrode (32) and the electro-optic layer (55), wherein the first material layer has a refractive index of 1.8 or less (SiO2, ¶[0066]).
Regarding claim 11, Yoshida further teaches the first material layer includes SiO2 (¶[0066]).
Regarding claim 12, Yoshida further teaches a first material layer (56) arranged between the electrode (32) and the electro-optic layer (55), wherein the first material layer has a relative dielectric constant of at least 8 or higher (TiO2, ¶[0066]).
Regarding claim 14, Yoshida further teaches the optical modulator has two optical waveguides serving as the core layer, an electrode that applies an electric signal to each of the two optical waveguides, a splitter that splits light to the two optical waveguides, and a multiplexer that multiplexes light from the two optical waveguides together, and the optical modulator modulates light guided through the two optical waveguides according to the electric signal (all inherent components of a modulated MZI as illustrated in Fig. 2).
Regarding claim 15, Yoshida teaches an optical transmitter-receiver (Fig. 1) comprising: an optical modulator element (5) that modulates light guided according to an electric signal (applied to signal electrode 32, Fig. 2); and an optical receiver element (6) that converts received light that is received, to an electric signal (outputted to DSP 3), wherein the optical modulator element includes: an electro-optic layer (PZT waveguide 31 of a PZT thin film 55) including an electro-optic material (PZT); a material layer (first cladding 54) arranged below the electro-optic layer and having a dielectric constant lower than a dielectric constant of the electro-optic layer (by way of TiO2 or SiO2); a core layer (Si waveguide 21) arranged below the material layer and having a refractive index higher than refractive indices of the electro-optic layer and the material layer (nSi>nTiO2, nSiO2, or nPZT); and an electrode (32) that applies an electric signal to the electro-optic layer, wherein the refractive index of the material layer is 0.85 times the refractive index of the electro-optic layer or higher (nTiO2>nPZT).
Regarding claim 17, Yoshida teaches an optical transceiver (Fig. 1) comprising: an optical modulator element (5) that modulates light guided according to an electric signal (applied to a signal electrode 32); an optical receiver element (6) that converts received light that is received, to an electric signal (to DSP 3); and a signal processor (DSP 3) that generates the electric signal to the optical modulator element and obtains the electric signal from the optical receiver element, wherein the optical modulator element includes: an electro-optic layer (PZT waveguide 31 of a PZT thin film 55) including an electro-optic material (PZT); a material layer (first cladding 54) arranged below the electro-optic layer and having a dielectric constant lower than a dielectric constant of the electro-optic layer (by way of TiO2 or SiO2); a core layer (Si waveguide 21) arranged below the material layer and having a refractive index higher than refractive indices of the electro-optic layer and the material layer (nSi>nTiO2, nSiO2, or nPZT); and an electrode (32) that applies an electric signal to the electro-optic layer, wherein the refractive index of the material layer is 0.85 times the refractive index of the electro-optic layer or higher (nTiO2>nPZT).
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.
Claim(s) 3, 5, 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida et al.
Regarding claims 3, 5, 13, while Yoshida does not specify the claimed ranges of dielectric constant or electro-optic coefficient, and by extension, the selected materials that has the physical properties within the claimed range. It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to perform routine experimentations using one of a finite amount of known, equivalent materials in the art, e.g., common EO materials such as lithium niobate, barium or strontium titanate, and/or other known cladding material having similar refractive indices as TiO2, as a matter of obvious engineering choice. In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960)
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida et al. as applied to claim 15 above, and further in view of U.S. PGPub 2010/0008675 A1 by De Dobbelaere. Yoshida teaches the optical transmitter-receiver including a light source (4) supplying light to the optical modulator element (5) and the optical receiver element (6) demodulating the received optical signal by using the light supplied from the light source (4) but does not specify the presence of a driver that drives the optical modulator element; and an amplifier that amplifies the electric signal from the optical receiver element. De Dobbelaere teaches an integrated transceiver comprising a transmitter and receiver components (124, 126) mount to or about a die (122), wherein the die can include a plurality of semiconductor electronic devices such as a laser driver and a transimpedance amplifier to facilitate operation of laser and photodiode. It thus would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to modify the invention by Yoshida by incorporating the driver and the amplifiers to facilitate the operation for the transceiver as stated by De Dobbelaere, for the purpose of controlling the light source, e.g., laser diode, and of converting the low-level photocurrent from the photoreceiver into a voltage signal for signal processing, as is well-known in the art.
Allowable Subject Matter
Claims 6, 7 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Yoshida is the closest identified prior art to the claimed invention but fails to teach or further suggest the electro-optic layer has a thickness in a range of 0.1 μm to 0.3 μm (Yoshida teaches 0.5-3 μm), the core layer has a thickness in a range of 0.05 μm to 0.10 μm (Yoshida teaches 100-300 nm), and the material layer has a thickness of 0.005 μm to 0.05 μm or less (Yoshida teaches 0.3-0.5 μm). Since the thickness ranges can differ by an order of magnitude or more, it is the examiner’s position that additional modification to arrive at the claimed limitations would not have been obvious or reasonable when considered in view of the rest of the limitations of the claimed invention.
Yoshida is the closest identified prior art to the claimed invention but fails to teach or further suggest a joint portion where an input waveguide connected to an input port of the optical modulator is connected to the core layer or a joint portion where an output waveguide connected to an output port of the optical modulator is connected to the core layer has a core thickness converter where thickness of the core layer is converted from a thickness of 0.05 μm to 0.10 μm, to a thickness of 0.15 μm or larger, when considered in view of rest of the limitations of the claimed invention.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. JP2014085398 discloses an optical modulator, in which a dielectric, low-index cladding layer (14) may be considered equivalent of the claimed material layer.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHARLIE PENG whose telephone number is (571)272-2177. The examiner can normally be reached 9AM - 6PM.
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/CHARLIE Y PENG/Primary Examiner, Art Unit 2874
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