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
Claim Objections
Claims 1 – 3, 5 – 9, and 11 – 18 are objected to because of the following informalities:
Claim 1 recites the limitation “dependent on the state” in which the article “the” causes an insufficient antecedent basis issue. For the purposes of this Action, the limitation is interpreted as “dependent on a state”.
Claim 7 twice recites the limitation “the length of” in which the article “the” causes an insufficient antecedent basis issue. For the purposes of this Action, each instance of the limitation is interpreted as “a length of”.
Appropriate corrections are required.
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 – 3, 5 – 9, 17 – 20, and 23 are rejected under 35 U.S.C. 103 as being unpatentable over Rios et al (WO 2017/046590 A1) in view of Mazed et al (US 2019/0253776 A1), and further in view of Abel et al (US 2017/0116515 A1).
Regarding claims 1 and 3, Rios discloses (e.g., Figs. 1 – 3, 23, and 24; 13:5 – 18:16 and 27:28 – 28:10) an optical element (switch) comprising (with reference to Fig. 23):
a first waveguide 105,
a second waveguide 117,101 and
a modulating element 102,
wherein:
the modulating element 102 is evanescently coupled to the second waveguide 117,101 (Abstract) and is arranged to modify a transmission or absorption characteristic of the second waveguide 117,101 (its part 101) dependent on a state (amorphous or crystalline) of the modulating element 102 (Fig. 3; 14:20 – 15:10); and
the state of the modulating element 102 is adjustable between a first (amorphous) state 202 (as denoted in Fig. 3) and a second (crystalline) state 201 by an optical field 125 carried by the second waveguide 117,101 (“Changing the state of the modulating element 102 may be achieved by inducing a phase-transition (or partial phase-transition) with an optical switching signal 125, which may comprise a more intense light pulse 135 than the probe pulses 107 of the probe signal 105. If the energy absorbed by the modulating element 102 is sufficient to heat it up to a transition temperature of the PCM, these pulses 135 can initiate either amorphization or crystallization” at 15:1 – 15:7).
Rios illustrates a variety of suitable/workable waveguide designs/types/topologies with the modulating element 102 (implemented as a phase-change material), such as a ring resonator in Fig. 23, a Mach-Zehnder interferometer in Fig. 24, and a waveguide reflector in Fig. 25, but does not expressly teach a directional coupler with a (phase-change material) modulating element. However, Mazed discloses (Fig. 1A; para. 0054 – 0081) a directional coupler 100A with a modulating element 120 formed by phase-change material (VO2). 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 teachings of Rios (the use of an optical field carried by a waveguide to change the state of a phase-change material in the same waveguide or a different waveguide) can be implemented in a directional coupler with a modulating element formed by a phase-change material, as another suitable/workable design/type expressly taught and explicitly illustrated by Mazed.
The Rios – Mazed combination is illustrated in Figure A below and considers an optical element comprising (with reference to Fig. 1A of Mazed) a first waveguide 180A, a second waveguide 180B and a modulating element 120 (phase-change material), wherein:
a cascaded first (left) and second (center) directional coupler are formed from a portion of the first and second waveguides 180A,180B in which the first and second waveguides are substantially parallel, evanescently coupled (para. 0052 of Mazed) and separated by a gap (narrowest gap in Fig. 1A); the modulating element 120 is evanescently coupled to the second waveguide 180B in the second (center) directional coupler and is arranged to modify a transmission or absorption characteristic of the second waveguide 180B dependent on a state (amorphous or crystalline) of the modulating element 120; and the state of the modulating element 120 is adjustable between a first (amorphous) and second (crystalline) state by an optical field carried by the first waveguide 180A and/or second waveguide 180B.
It is noted that the Rios – Mazed combination considers that the state of the modulating element can be adjusted electrically (with electrodes 160, as in Mazed) and/or optically (as in Rios). In the latter case, no electrodes are needed and faster switching may thereby be achieved due to all-optical switching.
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Figure A. An optical element of the Rios – Mazed combination (produced from Fig. 1A of Mazed) by eliminating electrodes.
The Rios – Mazed combination considers, by way of example but not limitation, that the contemplated optical element may be used as a switch for telecommunication application, but the Rios – Mazed combination does not expressly teach that the optical element may be used in a neural network and configured for its training. However, Abel discloses (Fig. 1; Abstract; para. 0021 – 0050) a neutral network 100 formed by nodes 110 that comprise optical elements with a phase-change material(s) (e.g., VO2 (para. 0034) which is the same material as in Mazed) whose state can be changed/modified by an optical field (para. 0035, 0049, and 0050) during/for training/learning of the network (para. 0021 – 0023 and 0027 – 0031). Mazed teaches that each node 110 may have 2 inputs and 2 outputs (as shown in Fig. 1) and lists a Mach-Zehnder waveguide interferometer as a suitable/workable type (para. 0028 and 0034) which is the same type as that shown in Fig. 24 of Rios. 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 optical device (directional coupler) of the Rios – Mazed combination can be comprised, in accordance with the teachings of Abel, in a neutral network and used during its training/learning. The use of a phase-change material(s) reduces power consumption.
The Rios – Mazed – Abel combination considers that the optical element can be an optical associative learning element (association with certain optical power levels for changing the state of the phase-change material) and fully covers all of the recited limitations, as detailed above.
Regarding claim 2, the Rios – Mazed – Abel combination considers that the modulating element is configured to modify the amount of coupling between the first and second waveguides in the second directional coupler dependent on the state of the modulating element (as taught by Mazed).
Regarding claim 5, the Rios – Mazed – Abel combination considers that the second directional coupler is covered by a phase-change material which has a higher refractive index and may cause an index mismatch at the interface between the first directional coupler (not covered by the phase-change material) and the second directional coupler. Hence, the Rios – Mazed – Abel combination renders obvious that a down-taper may be incorporated to reduce optical loss between the first directional coupler (with a lower refractive index) and the first directional coupler (with a higher refractive index), in similarity with tapers taught by Mazed for coupling to optical fibers (para. 0077 and 0078).
Alternatively or additionally, the Examiner takes official notice that tapered waveguide transitions are well known in the art and commonly used for reducing optical coupling loss between waveguides with different refractive indices.
Regarding claims 6 and 7, the Rios – Mazed – Abel combination considers an optical element that has essential structural features (a directional coupler with a phase-change material) and a principle of operation (all-optical changing of the state of the phase-change material) that are substantially identical/similar to those of the claimed element, while optimization of parameters defining the element would be well within ordinary skill in the art (which is noted as being high).
It is also noted that (i) the range limits depend on a particular application (a particular wavelength of operation, a particular wavelength used for all-optical switching); that (ii) the instant application does not provide any criticality for the exact values of the recited range limits; and that (iii) it has been held that discovering the optimum or workable ranges of prior art involves only routine skill in the art (In re Aller, 105 USPQ 233).
Regarding claims 8 and 9, the Rios – Mazed – Abel combination considers an optical element that has essential structural features (a directional coupler with a phase-change material) and a principle of operation (all-optical changing of the state of the phase-change material) that are substantially identical/similar to those of the claimed element, while optimization of operational parameters, such as relative optical power levels in the two waveguides as needed for state flipping/changing would be well within ordinary skill in the art (which is noted as being high).
Regarding claims 17 and 18, the Rios – Mazed – Abel combination considers an optical artificial neural network (Fig. 1 of Abel), comprising a plurality of the contemplated optical associative learning elements (as detailed above for claim 1), wherein at least two of the optical associative learning elements (comprised in nodes 110) are coupled/chained together (via connections 112), so that the output of the first waveguide of a first (left) one of the plurality of optical associative learning elements is coupled to the input of the first or second waveguide of a second (right) one of the plurality of optical associative learning elements.
Regarding claim 19, the teachings of Rios, Mazed, and Abel combine (see the arguments and motivation for combining, as provided above for claim 1) to teach expressly or render obvious all of the recited step limitations of a corresponding method of performing an associative learning operation in the optical domain, as detailed above for claim 1. Specifically, the Rios – Mazed – Abel combination considers a method of performing an associative learning operation in the optical domain using a device (directional coupler) comprising a first waveguide, a second waveguide and a modulating element (see Figure A provided above for claim 1), wherein:
a cascaded first and second directional coupler are formed from the portion of the first and second waveguides in which the first and second waveguides are substantially parallel, evanescently coupled and separated by a gap;
the modulating element is evanescently coupled to the second waveguide in the second directional coupler and is arranged to modify a transmission or absorption characteristic of the second waveguide dependent on the state of the modulating element, the method comprising:
providing first and second optical fields (first and second inputs) contemporaneously to the first and second waveguides respectively thereby modifying a state of the modulating element.
Regarding claim 20, Rios (Fig. 3) and Mazed (para. 0093 and 0094) each teach that modifying a state of the modulating element comprises changing the state of the modulating element from a more crystalline state to a less crystalline state, such as an amorphous state.
Regarding claim 23, the Rios – Mazed – Abel combination considers an optical element that has essential structural features (a directional coupler with a phase-change material) and a principle of operation (all-optical changing of the state of the phase-change material) that are substantially identical/similar to those of the claimed element, while optimization of operational parameters, such as relative optical power levels in the two waveguides as needed for state flipping/changing would be well within ordinary skill in the art (which is noted as being high).
Allowable Subject Matter
The subject matter pertaining to claims 11 – 16 and 22 would be allowable, if Applicant overcomes the applied objections and rewrites the claims in independent form including all of the limitations of the base claims and any intervening claims.
The reason for indicating allowable subject matter is that none of the prior art of record, taken alone or in combination, teaches expressly, renders obvious, and/or provides a motivation for a person of ordinary skill in the art to introduce an optical phase delay between optical fields arriving at the first directional coupler and thereby maximize an accumulated optical intensity in the second waveguide at the interface between the first directional coupler and the second directional coupler.
Conclusion
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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