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.
DETAILED ACTION
Applicant’s amendments and remarks filed 5/28/26 are acknowledged. Claims 1, 4, 10, 15 – 17, and 20 have been amended and claim 14 canceled. Claims 1 – 14 and 16 – 20 are pending.
Information Disclosure Statement
The IDS filed 6/16/26 has been received and considered by the Examiner.
Response to Amendments / Arguments
Applicant's amendments have obviated the objection to claim 20.
Applicant's amendments have obviated the previously-raised rejections under 35 USC 102 and necessitated new rejctions under 35 USC 103, as detailed below.
Applicant's arguments regarding the amended claims versus the previously-raised rejections under 35 USC 103(a) have been fully considered but they are moot in view of the new grounds of rejections, as necessitated by Applicant’s amendments. Specifically, the new limitations in the amended clams define relationships between the bandgaps of an active material and an passive material. Accordingly, the Examiner applies references by Yamazaki et al (JP 2012-63701) and Shields (US 5,963,358). Yamazaki discloses an electro-optic modulator with hybrid integration wherein an active section comprises an active material, such as lithium niobate of GaAs. Shields discloses an electro-optic modulator that comprises an active material, such as AlGaAs, and describes (well-known) relationships between the material bandgap and a photon energy required for phase modulation versus amplitude modulation.
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 – 6, 8, 10, 13, and 15 – 20 are rejected under 35 U.S.C. 103 as being unpatentable over Ren et al (CN 112558221 A) in view of Yamazaki et al (JP 2012-63701), and further in view of Shields (US 5,963,358), as evidenced by Wikipedia article “Band gap”.
Regarding claim 1, Ren discloses (Fig. 3; para. 0006 – 0009) a photonic assembly comprising (see annotated Fig. 3 below):
a first section (the coding chip disposed between the laser and the PMA in Fig. 3; para. 0008), the first section comprising a first substrate (comprising silicon dioxide; “Background” para. 0015); and
a second section PMA, the second section PMA comprising a second substrate (comprising lithium niobate; para. 0007 – 0009);
wherein the photonic assembly comprises an interferometer AMZI (an asymmetric Mach-Zehnder interferometer (AMZI) formed in the coding chip, as detailed in Figs. 2 and 3; para. 0003 and 0004), the interferometer comprising a plurality of passive photonic elements (a 2x2 splitter, a 2x2 combiner, a pair of parallel interferometer arms therebetween, and a delay line (Dt); para. 0003, 0004, and 0009) and a phase modulator (PM) PMA (para. 0007);
wherein the phase modulator PMA is provided on the second section (the modulator chip in Fig. 3); and
wherein the plurality of passive photonic elements (within AMZI) are provided on the first section (as seen in Fig. 3).
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Annotated Fig. 3 of Ren.
Ren generally renders obvious that the (high-speed) phase modulator PMA (for encoding) can be formed using an optical waveguide(s), but does not detail such embodiment. However, Yamazaki discloses (Fig. 24; para. 0046, 0141 – 0151, and 0167) a hybrid photonic assembly 2400 comprising a plurality of passive photonic elements (waveguides 2401,2402, 2x2 splitters, 2x2 combiners) in silica waveguides (para. 0142 – 0147) and a (high-speed) phase modulator formed in an active material substrate 2491 using optical waveguides (para. 0147 – 0149). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the (high-speed) phase modulator PMA (for encoding) in Ren can be formed using an optical waveguide(s), as generally rendered obvious by Ren and explicitly illustrated by Yamazaki, so that an integrated photonic assembly comprising both the interferometer and the phase modulator can be implemented (instead of two separate components that are lined by an optical fiber, as in Fig. 3 of Ren).
The Ren – Yamazaki combination considers a hybrid photonic assembly wherein:
the phase modulator is provided on the second (active) section and includes a same material as the second section,
the second section comprises an active material, such as lithium niobate (exemplified by Ren) or AlGaAs (para. 0046 of Yamazaki), the active material exhibiting an electro optic effect,
wherein the plurality of passive photonic elements are provided on the first section and include a same passive material, such as silica/SiO2 (para. 0147 of Yamazaki), as the first section.
While the Ren – Yamazaki combination does not recite a (well-known) relationship between the bandgap of a material and a photon energy at which the material is either transparent or absorbing, Shields discloses (Figs. 1 – 4; 4:30 – 6:13 and 13:6 – 14:54) an electro-optic phase modulator in an active material, such as GaAs (Fig. 4; 10:66 – 11:27) which is one of the active materials considered by the Ren – Yamazaki combination. Shields expressly teaches that the active material exhibits an electro-optic effect (1:13 – 18) in which a bandgap of the active material (e.g., GaAs) is modified by an electric field (created by electrodes 13,15,17) to modify a refractive index for light having a wavelength within a telecommunications wavelength range (Fig. 7; note that photon energies around 1.eV corresponds to wavelengths around 827 nm, i..e, within an IR wavelength range for telecommunications). Shields further teaches that the phase modulator switches a phase value of the photons (a photon energies A less than the bandgap of the active material, as shown in Fig. 1) in response to a voltage applied to the phase modulator and the applied electric field, the phase value being dependent on the applied voltage (8:10 – 14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the (high-speed) phase modulator of the Ren – Yamazaki combination, which is formed from the active material (e.g., GaAs, according to Yamazaki) and configured to switch a phase value of the photons at pulse frequencies used in quantum key distribution schemes (as taught by Ren at para. 0005 – 0009) in response to a voltage applied to the phase modulator and the applied electric field, has a bandgap of the active material larger than that of the photons and induces a phase value dependent on the applied voltage, as detailed by Shields, in order to enable the intended phase-modulation functionality for proper operation.
The Ren – Yamazaki – Shields combination considers that the first section comprises a passive material (e.g., silica/SiO2, as exemplified by Yamazaki) by having a larger bandgap than the bandgap of the active material (GaAs) of the second section and having a lower photon absorption coefficient than the second section for light having a wavelength within the telecommunications wavelength range (as evident from Fig. 1 of Shields which illustrate a well-known fact that optical absorption by a band edge decreased with a larger spectral separation of a photon and the band edge), wherein the passive material comprises a material (silica/SiO2) having a bandgap (~ 9eV) larger than an energy of photons (e.g., 1.5 eV (828 nm) in Fig. 7 of Shields; 0.8 eV (1,550 nm) at para. 0009 of Ren) propagating within the material, as evidenced by the Wikipedia article “Band gap” which shows (Table) that the bandgaps of GaAs and SiO2 are 1.43 eV and 9 eV, respectively.
In light of the foregoing analysis, the Ren – Yamazaki – Shields combination teaches expressly or renders obvious all of the recited limitations.
Regarding claim 2, the Ren – Yamazaki – Shields combination considers that the phase modulator is an electro-optic phase modulator, as intended for high-speed operation in Ren.
Regarding claim 3, the Ren – Yamazaki – Shields combination considers that the plurality of passive photonic components (in silica/SiO2) comprises one or more waveguides and, wherein the interferometer further comprises one or more additional waveguides (comprised in the parallel arms of the Mach-Zehnder interferometer, as shown in Fig. 24 of Yamazaki) provided on the second section, wherein at least one of the one or more waveguides is coupled to at least one of the one or more additional waveguides.
Regarding claim 4, Ren teaches (Figs. 1 – 3) the interferometer comprises a first optical path and a second optical path (interferometer arms),
wherein the plurality of passive elements comprises a first (input) coupler/splitter 1, a second coupler/combiner 2, and a delay line (creating a time delay of Dt),
wherein the first coupler couples an input of the interferometer to the input of the first optical path and to the input of the second optical path,
wherein the second coupler couples the output of the first optical path and the output of the second optical path, and
wherein the delay line is provided the first optical path or is provided in the second optical path.
Regarding claim 5, Ren teaches (see annotated Fig. 3 above) that the phase modulator PMA is provided at an (lower) output of the second (right) coupler.
Regarding claim 6, Ren teaches (see annotated Fig. 3 above) that the phase modulator (comprising a phase modulator portion disposed on the lower interferometer arm for setting a phase bias of the interferometer and the separate phase modulator portion PMA) is provided in the first (lower) optical path (Fig. 3; “the phase modulation electrode on the short arm (examiner’s note: lower interferometer arm) can be used for correcting the phase. then the two pulses coincident in time and the same polarization state are interfered on the 50/50 directional coupler” at para. 0005).
Regarding claim 8, Ren renders obvious that a (high-speed) phase modulation (encoding) can be imposed/encoded on input light (from the laser in Fig. 3) either after/down-stream the interferometer (as in Fig. 3) or before/upstream the interferometer without changing the principle of operation of the photonic assembly and a quantum communication system comprising thereof.
Regarding claims 10 and 13, Ren teaches (see annotated Fig. 3 above) that the interferometer comprises a first (lower) optical path and a second (upper) optical path; wherein plurality of passive elements comprises a first coupler (left/input 2x2) and a second coupler (right/output 2x2);
wherein the first (input) coupler couples (splits) an input of the interferometer (light from the laser) to the input of the first (lower) optical path and to the input of the second (upper) optical path, wherein the second (output) coupler couples the output of the first (lower) optical path and the output of the second (upper) optical path (as seen in Fig. 3), and
wherein the phase modulator (comprising a phase modulator portion disposed on the lower interferometer arm for setting a phase bias of the interferometer and the separate phase modulator portion PMA) is provided in the first (lower) optical path (as seen in Fig. 3).
Regarding claim 15, the Ren – Yamazaki – Shields combination considers that the passive material (silicon dioxide/SiO2) is optically passive for light having a wavelength (1,550 nm) within a first wavelength range (modulated light has a broader spectrum) and the active material (lithium niobate or GaAs) is (electro) optically active for light having a wavelength within the first wavelength range.
Regarding claim 16, the Ren – Yamazaki – Shields combination considers that a substrate of passive material (comprising silicon dioxide; “Background” para. 0015 of Ren), and the second substrate (of 1) is a substrate of (electro-optically) active material (comprising GaAs or lithium niobate).
Regarding claim 17, the Ren – Yamazaki – Shields combination considers that the second substrate is of a material comprising a III-V semiconductor material (e.g., GaAs).
Regarding claims 18 and 19, Ren teaches (para. 0006 and 0009) a quantum state encoder (at Alice’s site) comprising the disclosed photonic assembly.
Regarding claim 20, the teachings of Ren, Yamazaki, and Shields combine (see the arguments and motivation for combining, as provided above for claim 1) to teach expressly or render obvious all of the recited limitations, as detailed above for claim 1. Specifically, the Ren – Yamazaki – Shields combination considers a quantum communication system comprising a quantum state encoder (Alice’s encoder) and a quantum state decoder (Bob’s decoder) (Fig. 3; para. 0006 – 0009 of Ren),
wherein the quantum state encoder comprises (see annotated Fig. 3 provided above for claim 1 and a detailed explanation/mapping provide for it)
a first photonic assembly comprising a first section, the first section comprising a first substrate (comprising silicon dioxide; “Background” para. 0015); and
a second section, the second section comprising a second substrate; wherein the first photonic assembly comprises a first interferometer, the first interferometer comprising a first plurality of passive photonic elements and a first phase modulator;
wherein the first phase modulator is provided on the second section; and
wherein the first plurality of passive photonic elements are provided on the first section,
wherein the first interferometer comprises a first optical path and a second optical path;
wherein the first plurality of passive elements comprises a first coupler, a second coupler, and a first delay line;
wherein the first coupler couples an input of the first interferometer to the input of the first optical path and to the input of the second optical path,
wherein the second coupler couples the output of the first optical path and the output of the second optical path; and
wherein the first delay line is provided the first optical path or is provided in the second optical path,
wherein the first phase modulator is provided at an output of the second coupler;
and
wherein the quantum state decoder (at Bob’s site) has a structure similar to that of the encoder (as seen in Fig. 3) and comprises a second photonic assembly comprising:
a third section, the third section comprising a third substrate (comprising silicon dioxide; “Background” para. 0015); and
a fourth section PMB, the fourth section comprising a fourth substrate (comprising lithium niobate; para. 0007 – 0009);
wherein the second photonic assembly comprises a second interferometer, the second interferometer comprising a second plurality of passive photonic elements and a second phase modulator;
wherein the second phase modulator is provided on the fourth section; and
wherein the second plurality of passive photonic elements are provided on the third section,
wherein the second interferometer comprises a third optical path and a fourth optical path;
wherein the second plurality of passive elements comprises a third coupler, a fourth coupler, and a second delay line;
wherein the third coupler couples an input of the second interferometer to the input of the third optical path and to the input of the fourth optical path,
wherein the fourth coupler couples the output of the third optical path and the output of the fourth optical path; and
wherein the second delay line is provided the third optical path or is provided in the fourth optical path,
wherein the second phase modulator PMB is provided at an input of the third coupler,
wherein the phase modulator is provided on the second section and includes a same material (GaAs) as the second section,
wherein the second section comprises an active material (GaAs), the active material exhibiting an electro optic effect in which a bandgap of the active material is modified by an electric field to modify a refractive index for light having a wavelength (1,550 nm in Ren; 828 nm in Shield)s within a telecommunications wavelength range,
wherein the first plurality of passive photonic elements are provided on the first section and include a same material (SiO2) as the first section,
wherein the first section comprises a passive material (SiO2) having a larger bandgap 99 eV) than the bandgap (1.43 eV) of the active material (GasAs) of the second section and having a lower photon absorption coefficient than the second section for light having a wavelength within the telecommunications wavelength range (as detailed above for claim 1),
wherein the passive material comprises a material (SiO2) having a bandgap (9eV) larger than an energy of photons (0.8 eV – 1.5 eV) propagating within the material, and
wherein the phase modulator formed from the active material switches a phase value of the photons at pulse frequencies used in quantum key distribution schemes in response to a voltage applied to the phase modulator and the applied electric field (as intended by Ren), the phase value being dependent on the applied voltage.
Claims 7 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Ren in view of Yamazaki, in view of Shields, and further in view of Challener et al (US 2023/0393335 A1).
Regarding claim 9, the teachings of Ren, Yamazaki, and Shields combine (see the arguments and motivation for combining, as provided above for claim 3) to consider a hybrid photonic assembly wherein passive waveguides (e.g., in silicon or silicon dioxide) and electro-optic modulator (e.g., in lithium niobate) are integrated on a common support (as in Figs. 2 and 3 of Sugiyama). While the Ren – Yamazaki – Shields combination does not illustrate that the laser light source and a photodetector APD (in Fig. 3 of Ren) can also be integrated, Challener discloses (Figs. 3 and 27; para. 0050 – 0055, 0186, 0219, 0220, and 0227) an encoder/decoder of a quantum communication system that has at least one photo-detector (Ge photodiode in Fig. 27), wherein the at least one photodetector is coupled to an output of an interferometer (formed by two 2x2 couplers and comprising a delay line), wherein the at least one photo detector is provided on an electro-optically active second section (e.g. formed of III-V semiconductor materials; para. 0227) and integrated with a phase modulator(s) (as shown in Fig. 3).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the at least one photo-detector coupled to the output of the interferometer, as considered by the Ren – Yamazaki – Shields combination, can be provided/integrated on the second (electro-optic) section, as illustrated by Challener, in order to enable a mechanically rugged module of compact footprint.
Regarding claim 7, the Ren – Yamazaki – Shields – Challener combination renders obvious that the light source whose output of the light source is coupled to the input of the interferometer, can also be provided/integrated on the second section (e.g., formed on a III-V material which is a material suitable for making laser diode sources; “Steady progress is being made to integrate III-V components with Si chips because it also enables the presence of other active components light laser diodes” at para. 0227 of Challener).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Ren in view of Yamazaki, in view of Shields, and further in view of Challener et al (US 2023/0393335 A1).
Regarding claim 11, the Ren – Yamazaki – Shields combination does not teach a polarization sitter /combiner. However, Sugiyama discloses (Figs. 2 and 3; para. 0033 – 0052) a hybrid photonic assembly comprising a plurality of passive photonic elements (splitters/combiners 21,42) in silicon waveguides and a (high-speed) phase modulator formed in a lithium niobate substrate 12 using optical waveguides 31 (para. 0033). Sugiyama teaches the use of both (TE and TM) polarizations by using a polarization splitter and a polarization rotator (para. 0005 and 0009). The Ren – Yamazaki – Shields – Sugiyama combination renders obvious that the second coupler can a polarization splitter/combiner PBC (as PBC 45 in Fig. 2 of Sugiyama), wherein the interferometer further comprises a polarization rotator PR (which is described by Ren at para. 0009 and corresponds to PR 44 in Fig. 2 of Sugiyama), wherein the polarization rotator is provided in the first optical path or the second optical path.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Ren in view of Yamazaki, in view of Shields, and further in view of Wooten et al (US 2006/0056002 A1).
Regarding claim 12, the Ren – Yamazaki – Shields combination considers a Mach-Zehnder interferometer with a bent/folded topology (as in Fig. 24 of Yamazaki) and illustrates that such topology can be formed by waveguide U-turns. While the Ren – Yamazaki – Shields combination does not illustrate reflectors as an alternative means of folding optical paths, Wooten discloses (Figs. 3, 11, 20, and 32) Mach-Zehnder interferometers with a bent/folded topology and illustrates an embodiment with waveguide U-turns 3260a,3260b (Fig. 32; para. 0167 and 0168) and an embodiment with reflectors 1160a,1160b (Fig. 11; 0107 – 0110). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the plurality of passive photonic elements of the Ren – Yamazaki – Shields combination can additionally or alternatively comprise a first light reflector in the first optical path (one interferometer arm) and a second light reflector in the second optical path (the interferometer arm) as a suitable means for folding a Mach-Zehnder interferometer which is explicitly illustrated by Wooten.
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 extension fee 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 date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ROBERT TAVLYKAEV whose telephone number is (571)270-5634. The examiner can normally be reached 10:00 am - 6:00 pm, Monday - Friday.
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/ROBERT TAVLYKAEV/Primary Examiner, Art Unit 2896
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