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.
Response to Arguments
Applicant’s arguments with respect to claims 1-4 and 7-13 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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.
Claims 1 - 4
Claims 1-4 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (Silicon/III-V laser with super-compact diffraction grating for WDM applications in electronic-photonic integrated circuits, Opt. Express 19, 2006-2013 (2011); “Wang”) in view of Rickman et al. (2015/0207296; “Rickman”), further in view of Schmid et al. (Subwavelength Grating Structures in Silicon-on-Insulator Waveguides, Advances in Optical Technologies, 2008, 685489; “Schmid”), and further in view of Huang, Yingyan (2016/0109731; “Huang”).
Regarding claim 1, Wang discloses in figure 1, and related figures and text, laser embodiments, and related methods, comprising: “[A] heterogeneously integrated III-V-on-Silicon laser based on an ultra-large-angle super-compact grating (SCG). The SCG enables single-wavelength operation due to its high-spectral-resolution aberration-free design, enabling wavelength division multiplexing (WDM) applications in Electronic-Photonic Integrated Circuits (EPICs). The SCG based Si/III-V laser is realized by fabricating the SCG on silicon-on-insulator (SOI) substrate. Optical gain is provided by electrically pumped heterogeneous integrated III-V material on silicon. Single-wavelength lasing at 1550nm with an output power of over 2mW and a lasing threshold of around 150mA were achieved.” Wang, abstract and 2. Laser design principle (“The laser cavity is formed by mirror M and the SCG. The mirror M is at the end of the gain waveguide arm GW. Light from M first passes through a gain waveguide (GW) section, and then propagates to a waveguide mouth with width WSL, which serves as an entrance slit to SCG. SCG then diffracts the beam from slit WSL back to WSL and re-enter waveguide arm GW. The mirror M can be formed by a cleaved facet and serves as the output coupler…In this paper, the diffraction grating laser is realized on a Silicon/InP heterogeneously integrated platform. The diffraction grating is fabricated on the silicon layer and the waveguide section that provides the optical gain is fabricated on an evanescently coupled Si/InP region.”)
Wang – Figure 1
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Further regarding claim 1, Rickman discloses in figures 3 and 4, and related figures and text, integrated later configurations comprising Bragg Reflector waveguide arm configurations 31 and taper-assisted 41 vertical transitions/coupling between active/gain and passive regions. See below, Rickman – Selected Text.
Rickman – Figures 3 and 4
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Rickman – Selected Text
[0067] With reference to FIGS. 1 and 2, a first embodiment of a wavelength tunable silicon-on-insulator (SOI) laser, 1, 11, 12, 112 is shown, the laser comprising a laser cavity, made up of a semiconductor gain medium, 2 and a phase-tunable waveguide platform, 3 coupled to the gain medium.
[0068] The semiconductor gain medium has a front end, 21 and a back end, 22 and a mirror of the laser cavity is located at the back end. In the embodiment shown in FIG. 1, the semiconductor gain medium takes the form of a gain chip and the mirror, 10 at the back end of the cavity takes the form of a reflective surface (e.g. a dielectric coating) directly applied to the back end of the gain medium, in this case a reflective back facet of the gain chip. In the embodiment shown in FIG. 1 (a) the waveguide platform includes an SOI gain chip cavity for location of the gain chip.
[0069] The phase-tunable waveguide platform includes a first Distributed Bragg Reflector (DBR), 31 and a second Distributed Bragg Reflector (DBR), 32. In this embodiment, both the first and second DBRs have a comb reflectance spectrum as both are Sectioned Grating Distributed Bragg Reflectors (SG-DBRs). The waveguide platform is bifurcated with one SG-DBR in each arm.
[[0078] A second embodiment is described with reference to FIGS. 3 and 4, where like reference numerals correspond to those features described above in relation to FIGS. 1 and 2. The second embodiment differs from the first embodiment in that it includes a transition region, 41 located in-between the semiconductor gain medium and the 1.times.2 coupler at which a waveguide of a first height, T.sub.1 and first width (first ridge width), w.sub.1 is coupled to a waveguide of a second height , T.sub.2 and a second width (second ridge width) w.sub.2; the second height being less than the first height and the second width being less than the first width. In this case, the first and second Distributed Bragg Reflectors are each located in a waveguide of a second height, T.sub.2 and second width w.sub.2.
[0079] This embodiment with reduced waveguide dimensions can produce phase modulators with faster tuning speeds and lower power consumption, at the expense of adding the additional loss introduced by the mode transformer to the laser cavity.
[0080] A second transition region, 42 is located at the output of the laser cavity which forms a transition from the waveguide of the second height and width back to a waveguide having a first height and width.
[0081] As with the first embodiment, a third additional phase tuning device/region may be located between the gain medium and the 1.times.2 coupler. This may be located in-between the first transition region 41 and the 1.times.2 coupler.
[0082] FIG. 4 shows an example of a first or second transition region in the form of a taper. The taper couples a larger waveguide of a first height and width to a smaller waveguide of a second height and width so acts as both a "vertical taper" and a lateral taper. It comprises: a lower portion, 131 having a base "wedge-shaped" portion with laterally tapered sides that tapers the portion of the first slab region that is thicker than the second slab up to the second width (the width of the smaller waveguide); an intermediate portion, 132 which tapers a portion of the ridge above the first slab laterally from the larger waveguide width to the smaller waveguide width; and an upper "wedge" portion, 133 formed on top of the intermediate portion which tapers the portion of the ridge of the first height remaining above the second height to a point. The relative dimensions of the upper, intermediate and lower portions are chosen to maximise the coupling of light from the larger waveguide to the smaller waveguide in both a lateral and vertical direction relative to the waveguide platform.
[0083] The triple layer structure enables a transition to a different (thinner) slab thickness. The length of the transition region should be as short as possible to minimise the cavity length without introducing significant loss.
Consequently, it would have been obvious to one of ordinary skill in the art to integrate Wang’s device and method of fabrication embodiments with Rickman’s reflector and tapered configurations and methods to disclose a method for integrating one or more photonic devices on a substrate, wherein the photonic devices comprise one or more optical gain material areas, the method comprising: fabrication of one or more passive photonic components on a passive waveguiding layer, wherein the passive photonic components contain at least a curved optical grating and at least a wavelength-channel-combined-arm Bragg reflector; and transferring a thin layer of material capable of providing optical power amplification; Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text; because the resultant configuration and method would facilitate designing, fabricating, and implementing compact integrated lasers. Wang, abstract. Rickman, paragraph [0079].
Further in view of claim 1, Wang in view of Rickman does not explicitly disclose: “fabrication of at least one vertical beam coupling structure having an array of laterally tapering structures between the wavelength-channel-combined-arm Brag reflector and the one or more optical gain material areas.”
However, Schmid discloses waveguide embodiments comprising arrays of laterally tapering structures “Triangular SWG.” Schmid, figures 1 and 3, and related figures and text, for example, “In contrast to the square gratings, the antireflective properties of triangular gratings arise from the GRIN effect, as the effective refractive index varies continuously between the bulk values of the two media that comprise the grating,…” Schmid, page 3.
Schmid – Figures 1 and 3
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Consequently, in view of Schmid’s disclosure of the predictable reflection-control capabilities offered by arrays of laterally tapering structures, it would have been obvious to one of ordinary skill in the art to modify Wang in view of Rickman to disclose fabrication of at least one vertical beam coupling structure having an array of laterally tapering structures between the wavelength-channel-combined-arm Brag reflector and the one or more optical gain material areas because the resulting configuration would facilitate ‘increasing the optical mode energy overlapping with the quantum wells or bulk material.’ Huang, figure 7, and related figures and text, for example, paragraphs [0078] (“In as yet another aspect of the present invention, the waveguiding structure tapers down to a width smaller than a wavelength in the waveguiding material so as to strongly push the mode away from the lower transparent waveguiding structure towards the quantum wells or bulk material, thereby increasing the optical mode energy overlapping with the quantum wells or bulk material.”) and [0193] (“The beam from the SOI waveguide is then coupled into the thin-film modulator structure as shown by FIG. 7a/b using two tapers (one on the active material layer (e.g. InP/III-V), one on the primarily passive waveguide layer (e.g. Si)—see the top view). Due to the thin-thickness of the InP/III-V modulator's active layer structure (only 300-400 nm thick) for operation at 1550 nm wavelength range, this taper section can be very short (like 5-30 □m depending on the thickness) and over 95% of the energy can be transferred into the thin film modulator device. The output back into the optical fiber goes through a reverse process via two output tapers (one on the active material layer (e.g. InP/III-V), one on the primarily passive waveguide layer (e.g. Si)—see the top view) to bring the optical beam to the primarily passive waveguide layer (e.g. Si) and then to an output fiber-coupling lens.”)
Huang – Figure 7
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Regarding claims 2-4, it would have been obvious to one of ordinary skill in the art to modify Wang in view of Rickman, further in view of Schmid, and further in view of Huang’s embodiments, as applied in the rejection of claim 1, to disclose:
2. The method as claimed in claim 1, wherein the wavelength-channel-combined-arm Bragg reflector is fabricated into a planar waveguiding layer. Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text; Schmid, figures 1 and 3, and related figures and text; Huang, figure 7, and related figures and text.
3. The method as claimed in claim 2, wherein the wavelength-channel-combined-arm Bragg reflector is fabricated into a planar waveguiding layer with high-refractive index contrast. Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text; Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text; Schmid, figures 1 and 3, and related figures and text; Huang, figure 7, and related figures and text.
4. The method as claimed in claim 1, wherein the planar waveguiding layer is silicon. Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text; Wang, figure 1, and related figures and text; Schmid, figures 1 and 3, and related figures and text; Huang, figure 7, and related figures and text.
because the resultant configurations and methods would facilitate designing, fabricating, and implementing compact integrated lasers; Wang, abstract; Rickman, paragraph [0079]; while increasing the optical mode energy overlapping with the quantum wells or bulk material. Huang, figure 7, and related figures and text.
Claims 7 – 13
Claims 7-13 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (Silicon/III-V laser with super-compact diffraction grating for WDM applications in electronic-photonic integrated circuits, Opt. Express 19, 2006-2013 (2011); “Wang”) in view of Rickman et al. (2015/0207296; “Rickman”), further in view of Schmid et al. (Subwavelength Grating Structures in Silicon-on-Insulator Waveguides, Advances in Optical Technologies, 2008, 685489; “Schmid”), and further in view of Huang, Yingyan (2016/0109731; “Huang”), as applied in the rejection of claims 1-4, and further in view of Trita, Andrea (2017/0351025; “Trita”).
Regarding claims 7-13, Trita discloses in figures 3, 4, and 6, waveguide ‘entrance’ and ‘curved’ regions: “A single mode waveguide with a straight portion and a curved portion, the curved portion having the shape of an adiabatic bend.” Trita, abstract; paragraph [0003] (“[0003] Large single mode rib waveguides have been proposed to guide light along various paths of an integrated circuit as they allow relaxed fabrication tolerances and easier coupling to an external optical fiber. Due to the large cross section, transient propagation of leaky high order modes is possible in large single mode rib waveguides, which may have effects tending to degrade the performance of a photonic integrated circuit. Thus, there is a need for an improved system and method for minimizing transient propagation of leaky high order modes in large optical rib waveguides.”), paragraph [0008] (“[0008] In one embodiment, each of the tapered rib waveguides has a rib having: a first width at a first end of the first input star coupler aperture adjacent the first free-propagation region, and a second width at a second end of the first input star coupler aperture, the second end being opposite the first end of the first input star coupler aperture, the first width being at least 30% greater than the second width.”), and paragraph [0044] (“Light may also couple to one or more higher order modes where light is coupled into a waveguide from one of the free-propagation regions if the phase fronts of the free-space waves are not perpendicular to the optical axis of the waveguide. This may occur, for example, for some of the field patterns launched (from points that are off center) into the second free-propagation region 135, when one or more of the plurality of second waveguides 145 is an input of the arrayed waveguide grating. For example, in FIG. 2A, light coupling from the second free-propagation region 135 to the straight portion 240 may couple into a superposition of the fundamental mode 250 and a higher order mode 255. The straight portion 240 may be tapered and, as a result of its taper, may have the property that it would exhibit strong coupling between either fundamental mode and one or more leaky higher order modes if it were curved..”)
Consequently, it would have been obvious to one of ordinary skill in the art to modify Wang in view of Rickman, further in view of Schmid, and further in view of Huang’s embodiments, as applied in the rejection of claims 1-4, to disclose:
7. The method as claimed in claim 6, wherein one side of the optical beam propagating path intersects with the wavelength-channel-combined-arm Bragg reflector, and another side of the optical beam propagating path intersects with the curved diffraction grating is positioned the mouth of a channel waveguide (called wavelength-channel-separated waveguide mouth). Trita, figures 3, 4, and 6, and related figures and text; Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text.
8. The method as claimed in claim 7, wherein the optical power in a wavelength of light in the optical beam propagating toward the wavelength-channel-combined-arm Bragg-grating reflector is reflected back either fully or partially by the wavelength-channel-combined-arm Bragg-grating reflector toward the curved diffraction grating and is further diffracted by the curved diffraction grating to enter the wavelength-channel-separated waveguide mouth. Trita, figures 3, 4, and 6, and related figures and text; Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text.
9. The method as claimed in claim 8, further comprising a plurality of waveguide mouths, with each waveguide mouth receiving a wavelength of the light beam reflecting back from the wavelength-channel-combined-arm Bragg reflector towards the grating. Trita, figures 3, 4, and 6, and related figures and text; Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text.
10. The method as claimed in claim 9, wherein the light beam entering the mouth of a channel waveguide is guided via a linear or a curvilinear path along a channel waveguide to an optical gain region. Trita, figures 3, 4, and 6, and related figures and text; Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text. Trita, figures 3, 4, and 6, and related figures and text; Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text.
11. The method as claimed in claim 10, wherein the optical gain region is composed of an active gain material layer forming a gain channel waveguide bonded on top of a passive transparent channel waveguide. Trita, figures 3, 4, and 6, and related figures and text; Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text.
12. The method as claimed in claim 11, wherein the optical beam energy in the passive transparent channel waveguide is transferred from the passive channel waveguide to the gain material layer via the array of laterally tapering structures on at least one of the passive channel waveguiding layer or the gain channel waveguide layer. Trita, figures 3, 4, and 6, and related figures and text; Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text.
13. The method as claimed in claim 12, wherein the optical beam energy in the gain channel waveguide is transferred from the gain channel waveguide to the passive channel waveguide via the array of laterally tapering structures on at least one of the passive channel waveguiding layer or the gain channel waveguide layer. Trita, figures 3, 4, and 6, and related figures and text; Wang, figure 1, and related figures and text; Rickman, figures 3 and 4, and related figures and text.
because the resultant configurations and methods would facilitate controlling optical losses; Trita, paragraph [0044]; while designing, fabricating, and implementing compact integrated lasers; Wang, abstract; Rickman, paragraph [0079]; while increasing the optical mode energy overlapping with the quantum wells or bulk material. Huang, figure 7, and related figures and text.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 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