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.
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.
Claim(s) 1-3 and 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zilkie et al. (U.S. Patent Application Pub. 2019/0310496 A1) in view of Shindo et al. (WIPO Pub. WO2021059447 A1), Skogen (U.S. Patent 12,355,209 B1) and Ishizaka (U.S. Patent Application Pub. 2010/0086255 A1). In the following explanation, U.S. Patent Application Pub. 2022/0352692 A1 is used as an English translation of Shindo et al.
Regarding claim 1, Zilkie et al. teaches in FIG. 3B an optical transmitter, comprising: a distributed feedback (DFB) laser 201 having an active region formed as a multiple quantum well (see paragraph [0030]); an electro-absorption (EA) modulator (EAM) having an absorption region formed as a multiple quantum well; a semiconductor amplifier (SOA); a bent waveguide that rotates a light propagation direction by an angle θwg (the waveguide in FIG. 3B rotates the light propagation by an angle of 180°); and wherein the DFB laser, the EA modulator, the SOA, the bent waveguide, are monolithically integrated on one substrate.
The differences between Zilkie et al. and the claimed invention are (a) Zilkie et al. does not teach that the laser generates an optical gain by current injection and a diffraction grating, (b) Zilkie et al. does not teach that the EAM has composition different from a composition of the DFB laser and the SOA has an active region having a same composition as the composition of the DFB laser, (c) a passive waveguide having a tapered region and a narrow waveguide region, the tapered region converts a width W1 of the passive waveguide connected to the SOA into a width W2 of the narrow waveguide region, where W1 > W2 is satisfied, and the passive waveguide forms the angle θwg with respect to a normal line to an end surface of the substrate and is in contact with the end surface of the substrate.
Shindo et al. teaches in FIG. 2 an optical transmitter comprising a DFB laser, an EAM and a SOA. Shindo et al. teaches in paragraph [0004] the DFB laser has a driving current and a diffraction grating. Shindo et al. teaches in paragraph [0004] that the EAM has a composition different from that of the DFB laser and in paragraph [0009] that the SOA has an active region with an identical composition as the active region of the DFB laser. One of ordinary skill in the art would have been motivated to combine the teaching of Shindo et al. with the optical transmitter of Zilkie et al. because Shindo et al. provides the details of implementation that are missing from Zilkie et al. Thus it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use current injection and include a diffraction grating in the DFB laser, use the same composition as the DFB laser active region for the SOA and use different composition as the DFB laser for the EAM, as taught by Shindo et al., in the optical transmitter of Zilkie et al.
The combination of Zilkie et al. and Shindo et al. still fails to teach a passive waveguide with a tapered region and a narrow waveguide region. Skogen teaches in FIG. 1 a SOA with a spot-size converter region 180 so that the output optical mode has a good overlap with an output optical fiber. Ishizaka teaches in FIG. 11 that a spot-size converter has a taper region 14 and a linear region 13. One of ordinary skill in the art would have been motivated to combine the teaching of Skogen and Ishizaka with the modified system of Zilkie et al. and Shindo et al. because a spot-size converter provides an output optical mode that has a good overlap with an output fiber. Thus it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a spot-size converter at the output of the transmitter, as taught by Skogen and Ishizaka, in the modified system of Zilkie et al. and Shindo et al. The Examiner notes that Zilkie et al. teaches that the passive waveguide forms an angle of 180° with respect to a normal line to the end surface (the bottom surface of FIG. 3B of Zilkie et al.).
Regarding claim 2, Zilkie et al. teaches in FIG. 6 that a plurality of optoelectronic devices can be disposed on a single wafer or chip.
Regarding claim 3, Zilkie et al. teaches that the substrate is an InP substrate (see paragraph [0030]), the DFB laser, the EA modulator, and the SOA are formed on a (100) surface of the InP substrate, the DFB laser has an optical axis in a direction of a substrate crystal orientation [011], and the passive waveguide forms an angle of 180° with respect to the substrate crystal orientation [011] and is in contact with the end surface of the substrate (see FIG. 3B).
Regarding claim 10, Zilkie et al. teaches in paragraph [0043] that the pitch (the distance between the output waveguide in device 200a and the respective output waveguide in device 200b) is less than 250 μm. Even though Zilkie et al. does not teach the exact value as claimed. However, the Examiner recognizes that the claimed difference exists not as a result of an attempt by applicant to solve a problem but merely amounts to selection of expedients known to the artisan of ordinary skill as design choices.
Allowable Subject Matter
Claims 4-9 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.
Response to Arguments
Applicant's arguments filed 28 August 2026 have been fully considered but they are not persuasive.
The Applicant argues:
As the Office Action notes, Skogen discloses providing an "optional spot-size converter region 180" on the output side of the SOA so that "the output optical mode has a good overlap with an output optical fiber." Skogen describes reducing the core thickness in spot-size converter region 180, thereby expanding the diameter of the output optical signal to provide good overlap with an output optical fiber.
Ishizaka discloses a "spot size conversion portion" at an input/output portion of an optical waveguide for reducing coupling losses. Ishizaka explains that spot-size conversion enlarges the spot size to reduce coupling losses with an optical fiber or other optical waveguide element.
However, the purpose and configuration of the presently claimed invention are distinct from those disclosed in Skogen and Ishizaka. Claim 1 does not simply recite a generic spot-size converter positioned at an optical output. Instead, claim 1 expressly requires that "the passive waveguide has a tapered region and a narrow waveguide region" and that "the tapered region converts a width W1 of the passive waveguide connected to the SOA into a width W2 of the narrow waveguide region," where W1 > W2. Claim 1 further requires that this passive waveguide form the angle θwg with respect to a normal line to the substrate end surface and be in contact with the end surface.
The argument is not persuasive. Skogen and Ishizaka, in combination of Zilkie et al. and Shindo et al., teach the above structure as recited in claim 1. In particular, Ishizaka teaches in FIG. 11 a passive waveguide converts a width W1 (the width of region 14 at the input of the passive waveguide) into a width W2 (the width of region 13) of the narrow waveguide region where W1>W2. Zilkie et al. further teaches that the passive waveguide forms an angle of 180° with respect to a normal line to the end surface (the bottom surface of FIG. 3B of Zilkie et al.)
The argument continues:
The purpose of this particular configuration is described in the present specification. Paragraph [0058] explains a light beam shape is enlarged "by narrowing a width of the waveguide by tapering." Because the light beam consequently propagates while spreading, the configuration can "obtain the same reflection suppression effect as that of the window region." Thus, rather than merely seeking efficient coupling of an output optical mode into an optical fiber, the claimed narrowing is used to reduce the proportion of reflected light that couples back into the waveguide and thereby suppress reflected return light from the semiconductor-chip end surface.
The argument is not persuasive. In response to applicant's argument that the references fail to show certain features of applicant's invention, it is noted that the features upon which applicant relies (i.e., reducing reflected light) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Further, Ishizaka teaches the same structure and, therefore, the modified optical transmitter based on Ishizaka’s teaching has the same feature.
The argument continues:
The narrow waveguide region additionally addresses a manufacturing problem associated with formation of the chip end surface by cleavage. As explained in paragraph [0059], the narrow waveguide region is arranged beyond the designed cleavage position and has sufficient length to accommodate position-shift error in the cleavage process. Consequently, "even in a case where the cleavage position is shifted, the end surface is always formed in the narrow waveguide region," thereby avoiding an adverse effect on the quality of the emitted beam. Paragraph [0060] further explains that an approximately ±10 pm position-shift error occurs during cleavage and that the narrow waveguide region therefore requires sufficient length "to compensate for the error," while also retaining sufficient narrow-waveguide length to obtain the reflection- suppression effect.
The argument is not persuasive. In response to applicant's argument that the references fail to show certain features of applicant's invention, it is noted that the features upon which applicant relies (i.e., solving a manufacturing problem) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims.
The argument continues:
Accordingly, an objective of the "tapered region and a narrow waveguide region" is not simply spot-size conversion for good overlap with an optical fiber. Rather, the claimed configuration enlarges the beam shape at the chip end surface to suppress end-surface reflection while also providing tolerance for cleavage-position shift. These purposes are quite distinct from the reason relied upon by the Examiner for the spot-size converters of Skogen and Ishizaka, namely, improving coupling between an optical output and an optical fiber. The Office Action does not explain why a person of ordinary skill seeking improved fiber coupling would have been led to the tapered and narrow passive-waveguide arrangement of claim 1, much less to that arrangement in which the narrow passive waveguide itself extends to the substrate end surface at the claimed angle.
The argument is not persuasive. In response to applicant's argument that there is no suggestion to combine the references, the examiner recognizes that obviousness can only be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988) and In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992). In this case, one of ordinary skill in the art would have been motivated to combine the teaching of Skogen and Ishizaka with the modified system of Zilkie et al. and Shindo et al. because a spot-size converter provides an output optical mode that has a good overlap with an output fiber. Thus it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a spot-size converter at the output of the transmitter, as taught by Skogen and Ishizaka, in the modified system of Zilkie et al. and Shindo et al.
The argument continues:
These structural differences further demonstrate that the stated reason for combining the references does not explain why a person of ordinary skill would have modified the references to arrive at the particular arrangement recited in claim 1. Skogen concerns an SOA having variable optical confinement along the length of the device. Its optional spot-size converter region 180 operates by reducing the thickness of the core so that the output optical mode expands for improved overlap with an output optical fiber. Thus, Skogen does not teach the passive waveguide of claim 1 connected to the SOA having a tapered region that converts a lateral waveguide width W1 into a smaller lateral width W2 of a narrow waveguide region that contacts the substrate end surface at the claimed angle.
The Examiner disagrees. There is no structure difference between the combination of Zilkie et al., Shindo et al., Skogen and Ishizaka as explained above and in the Claim Rejections - 35 USC § 103 Section.
The argument continues:
Ishizaka is directed to an SOA optical waveguide having tapered structures that vary the width and/or thickness of silicon core layers to transfer the optical field and enlarge its spot size. Ishizaka does not provide the missing teaching of arranging a narrowed passive-waveguide region downstream of the SOA such that the narrowed region itself extends to and contacts the substrate end surface at the claimed angle, much less for the combined purposes of both suppressing reflected return light and accommodating cleavage-position error.
The argument is not persuasive. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
The Applicant’s argument continues:
In effect, Skogen and Ishizaka change or enlarge the optical mode to improve coupling with an optical fiber. In contrast, the claimed passive-waveguide configuration narrows the waveguide from W1 to W2 and extends the resulting narrow region to the substrate end surface at the claimed angle. As explained in the specification, this configuration enlarges or spreads the beam to suppress reflected return light and also provides tolerance for cleavage-position error. Skogen and Ishizaka do not disclose or suggest this claimed arrangement.
The argument is not persuasive. In response to applicant's argument that the references fail to show certain features of applicant's invention, it is noted that the features upon which applicant relies (i.e., this configuration enlarges or spreads the beam to suppress reflected return light and also provides tolerance for cleavage-position error) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
The rest of Applicant’s argument is just repeating what has been discussed above.
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 SHI K LI whose telephone number is (571)272-3031. The examiner can normally be reached M-F 6:53 a.m. -3:23 p.m.
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skl11 September 2026
/SHI K LI/Primary Examiner, Art Unit 2635
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