Notice of Pre-AIA or AIA Status
The present application, filed after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Specification
The abstract is objected to because line 2 reads "n" instead of "an", and because line 5 reads "that" instead of "the".
The specification is objected to because [0028] refers to Fig. 5 but there is no figure 5 in the file (only figures 5A-5D, which are separately mentioned in [0029]-[0032]). It appears that [0028] should be deleted.
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.
Claims 1, 5-8, and 12-14 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Qiu et al. (article in Optics Letters, September 2020, citation "U" on attached 892 form).
Claim 1: Qiu discloses a thermo-optical phase shifter comprising a cladding and an optical waveguide core (p. 4808 left column, first full paragraph),
wherein the cladding is configured to surround the optical waveguide core (fig. 3(a)); and
the optical waveguide core comprises a first section and a second section, dimensions of the first section and the second section are set to have different dimensions (one has a width of 450 nm and the other has a width of 600 nm, see especially figs. 1(b) and 3(a)), and the optical waveguide core is distributed in a spiral shape (figs. 1(a)-(b), 2(e), and 3(b); p. 4807 left column first and second full paragraphs).
Claim 5: The optical waveguide core further comprises a bridge structure ("bent connector" in Qiu terminology), one end of the bridge structure is connected with the first section, and the other end of the bridge structure is connected with the second section (see the bent waveguide with Rmin of 1.8 µm in fig. 1(b)). In particular the bridge structure is one of the "two bent connectors with the smallest radius of 1.8 µm, which connect two waveguides with different widths (WL and WS)" mentioned at p. 4807 left column second full paragraph.
Claim 6: A bending portion of the optical waveguide core and the bridge structure comprise at least one of an arc shape, a line bending shape, an Euler bending shape and a sinusoidal shape (at least an arc shape as illustrated).
Claim 7: A dimension of the bridge structure gradually increases from one end to the other end ("a taper is set between them", p. 4807 left column second full paragraph).
Claim 8: The bridge structure comprises a first bridge structure portion and a second bridge structure portion, wherein the first bridge structure portion is a bend waveguide with a uniform dimension, and the second bridge structure portion is a straight waveguide with the dimension gradually changing from one end to the other end (fig. 2(a)).
Claim 12: A material of the optical waveguide core comprises at least one of silicon, silicon nitride, silicon dioxide, aluminum oxide, lithium niobate, polymer, germanium and III-V materials (silicon in particular).
Claim 13: A waveguide type of the optical waveguide core comprises at least one of a channel waveguide, a ridge waveguide, a slot waveguide and a diffused waveguide (for example, a channel waveguide).
Claim 14: A wavelength of the optical waveguide core includes, but is not limited to, at least one of a visible light range, a O-band, a C-band and a mid-infrared range (silicon is transparent over at least the O and C bands and a mid-infrared range; a tested embodiment used wavelengths within the C-band as shown in fig. 4(c)).
Claims 1-3, 5-6, and 10-14 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US 2020/0363661 A1. Note that the spiral arrangement of fig. 5B is an alternative to the serpentine arrangement of fig. 3A (last sentence of [0035]).
Claim 1: '661 discloses a thermo-optical phase shifter comprising a cladding 316 and an optical waveguide core 304 (figs. 3A-3C),
wherein the cladding is configured to surround the optical waveguide core (fig. 3B); and
the optical waveguide core comprises a first section and a second section (at least 534 and 536), dimensions of the first section and the second section are set to have different dimensions (see discussion in [0037]-[0039]), and the optical waveguide core is distributed in a spiral shape (fig. 5B, [0048]).
Claim 2: The thermo-optical phase shifter further comprises a resistive heater 312 (also note "Active Heater Region" in fig. 5B), and wherein the resistive heater is surrounded by the cladding (the heater can be within cladding 316 as stated in [0053], note also claim 16) and located on one side (an upper side) of the optical waveguide core, and the resistive heater is separated from the optical waveguide core by the cladding (fig. 3B).
Claim 3: The optical waveguide core has resistance performance through ion doping ([0053] fourth through sixth sentences).
Claim 5: The optical waveguide core further comprises a bridge structure (the curved section joining 534 to 536 in fig. 5B), one end of the bridge structure is connected with the first section 534, and the other end of the bridge structure is connected with the second section 536.
Claim 6: A bending portion of the optical waveguide core and the bridge structure comprise at least one of an arc shape, a line bending shape, an Euler bending shape and a sinusoidal shape (at least an arc shape).
Claim 10: The thermo-optical phase shifter further comprises a plurality of third sections (at least 532 and 538) and a plurality of bridge structures (at least the curved sections joining 532 to 538 and 534 to 540) wherein a number of the third sections is N and a number of the bridge structures is M, dimensions of the N third sections are different, and the dimensions of two spatially adjacent sections of the thermo-optical phase shifter are set to be different.
Claim 11: A material of the resistive heater comprises at least one of titanium nitride, doped silicon, tungsten and gold ([0053] mentions at least doped silicon; note also fig. 7A and claim 18).
Claim 12: A material of the optical waveguide core comprises at least one of silicon, silicon nitride, silicon dioxide, aluminum oxide, lithium niobate, polymer, germanium and III-V materials (particularly silicon).
Claim 13: A waveguide type of the optical waveguide core comprises at least one of a channel waveguide, a ridge waveguide, a slot waveguide and a diffused waveguide (for example a channel waveguide as shown in fig. 3B or a ridge waveguide as shown in fig. 3D).
Claim 14: A wavelength of the optical waveguide core includes, but is not limited to, at least one of a visible light range, a O-band, a C-band and a mid-infrared range
(silicon is transparent over at least the O and C bands and a mid-infrared range).
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 9 is rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0363661 A1 (applied above) in view of Murray et al. (article in Optics Express, July 2015, citation "V" on attached 892 form).
'661 does not disclose an air trench or air undercut for thermal insulation arranged or formed in the cladding, wherein the air trench or air undercut is located around the optical waveguide core (fig. 3B). Murray discloses a similar thermo-optic phase shifter which is also based on compactly arranged dissimilar waveguide cores (figs. 3 and 5). Fig. 5(d) of Murray shows such a device including an air trench or air undercut arranged in the cladding material around its waveguide cores. The effect of the trench / undercut is to significantly reduce the power required to achieve a given phase shift compared to a device without the trench / undercut (Table 2; every underetched value is at least 10 times smaller than the corresponding unetched value, and in the case of Device 5 is over 40 times smaller). A person of ordinary skill in the art could have modified the '661 device by forming an air trench / air undercut around its optical waveguide core in the manner suggested by Murray with predictable results, and would have had a reasonable expectation of success since similar materials and similar cross-sectional configurations are involved. Thus it would have been obvious to such a person before the effective filing date of claim 9 to do so. A motivation would have been a desire to reduce the power requirements of the '661 device.
Conclusion
The additional references listed on the attached 892 form are considered generally relevant to the subject matter of this application. Many of them disclose further examples of devices having spiral waveguide layouts and/or dissimilar waveguide cores.
Contact Information
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Official correspondence by fax: 571-273-8300
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/Michael Stahl/Primary Examiner, Art Unit 2874
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