DETAILED 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 .
Claim Rejections - 35 USC § 102
(a)(1) the Regarding 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 Regarding
Claims 17-20 are rejected under 35 U.S.C. 102 (a)(1) as being anticipated over
Jianhua Wu et.al (hereinafter Wu) US 2022/0179159 A1.
Claim 17:
- A computer program product for performing optical neural network computations,
[0147]:
FIG. 14 is a schematic diagram of an example of an artificial neural network (ANN) computation system.
[0388]:
A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language
0387] The digital controller (e.g., for controlling the components shown in FIG. 24E) and the functional operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware
- the computer program product comprising a computer-readable storage medium having program code embodied therewith, the program code comprising computer-readable program code configured to cause a processor to perform the steps of:
[0387]:
Embodiments of the subject matter described in this specification can be implemented using one or more modules of computer program instructions encoded on a computer-readable medium for execution by, or to control the operation of, data processing apparatus. The computer-readable medium can be a manufactured product, such as hard drive in a computer system or an optical disc sold through retail channels, or an embedded system. The computer-readable medium can be acquired separately and later encoded with the one or more modules of computer program instructions, such as by delivery of the one or more modules of computer program instructions over a wired or wireless network. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, or a combination of one or more of them
[0389]:
The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).
- emitting a beam from a photonic crystal surface emitting laser (PCSEL) array; modulating phase and/or amplitude of the emitted beam;
[0028]:
The beam-redirecting element can include a first surface that is configured to reflect the first optical beam into the first coupler, and a second surface that is configured to reflect the second optical beam into the second coupler.
[0194]]:
FIG. 1 shows an example of a photonic computing system 100. The system 100 includes a photonic source 102 (e.g., a laser bar) attached to a submount 106, which is attached to a support structure 104 (e.g., a silicon-based substrate).
[BRI: Perhaps it is known to a POSITA that a beam-redirecting element can indeed incorporate a first surface that is a photonic crystal surface, and in fact, photonic crystal-based designs are actively being used for beam steering and redirection. Perhaps it is also known to a POSITA in semiconductor manufacturing, a silicon-based substrate is typically a single-crystal silicon wafer, which is a true crystal structure]
- receiving a communication from a photodetector based on the emitted beam; and performing a linear or non-linear beam control operation based at least in part on the communication received from the photodetector.
[0254]:
In some implementations, the photonic computing system includes two or more photonic integrated circuits mounted on an interposer. The interposer can include optical waveguides and optical couplers that provide optical signal paths to enable optical signals to be communicated between or among the two or more photonic integrated circuits
[0283]:
In FIG. 20B, the optical signals are detected in a common-terminal configuration where two photodiode detectors are connected to a common terminal 2032 (e.g., the inverting terminal) of an op-amp 2030. In this configuration, a current 2010 generated from a first photodiode detector 2012 and a current 2014 generated from a second photodiode detector 2016 combine at a junction 2018 among three conductors to produce a difference current 2020 between current 2010 and the current 2014,
[0260]:
computations can be performed using these operations, which represent a set of general linear operations from which a variety of computations can be performed, including but not limited to: vector-vector dot products, vector-vector element-wise multiplication, vector-scalar element wise multiplication, or matrix-matrix element-wise multiplication.
[0268]:
The optical signal encoded with the vector element
x
A
can be encoded using
different forms of amplitude modulation,
[0268]:
the power of a laser source can be modulated to have a particular power level from a predetermined set of multiple power levels,
[0268]:
The fraction of time that the power is at the “on” level corresponds to a particular energy level. Either of these particular values of power or energy can be mapped to a particular
value of the element
x
A
(using a linear or nonlinear mapping relationship).
Claim 18:
Wu discloses:
- wherein the modulation comprises beam angle, coupling between emitters, and/or intensity.
[0269]:
the term “amplitude” may refer to the magnitude of the signal represented by the instantaneous or integrated power in the optical wave, or may also equivalently refer to the “electromagnetic field amplitude” of the optical wave. This is because the electromagnetic field amplitude has a well-defined relationship to the signal amplitude (e.g., by integrating an electromagnetic field intensity, which is proportional to the square of the electromagnetic field amplitude, over a transverse size of a guided mode or free-space beam to yield the instantaneous power). This leads to a relationship between modulation values, since a modulator that modulates the electromagnetic field amplitude by a particular value √{square root over (M)} can also be considered as modulating the power-based signal amplitude by a corresponding value M (since the optical power is proportional to the square of the electromagnetic field amplitude).
Claim 19:
Wu discloses:
- wherein the system is configured to create an optical neural network, to perform photonic computation, or to perform neuromorphic computation.
[Abstract]:
A method for assembling a photonic computing system includes attaching a photonic source to a support structure, and attaching a photonic integrated circuit to the support structure. The photonic source includes a first laser die on a substrate configured to provide a first optical beam, and a second laser die on the substrate configured to provide a second optical beam. The photonic integrated circuit includes a first waveguide and a first coupler coupled to the first waveguide, and a second waveguide and a second coupler coupled to the second waveguide. The method includes attaching a plurality of beam-shaping optical elements to the support structure, the substrate, or the photonic integrated circuit, in which the attaching includes aligning a first beam-shaping optical element during attachment so that the first optical beam is coupled to the first coupler, and aligning a second beam-shaping optical element during attachment so that the second
Claim 20:
Wu discloses:
- wherein the communication received from the photodetector comprises a summation of differential signals.
[0288]:
The system configuration 2110 also includes other modules arranged as shown in FIG. 21B to provide two different output electrical signals that represent an output vector that is the result of the vector-matrix multiplication performed by system 100. There are 16 different multiplication modules 1904 modulating different copies of the optical signals representing the input vector, and there are 16 different optical detection modules 1906 to provide electrical signals representing intermediate results of the computation. There are also two different summation modules 2114A and 2114B that compute the overall summation for each of the output electrical signals. In the figure, the signal lines electrically coupling the optical detection modules 1906 to the summation module 2114B are shown in dashed lines. Because each overall summation can include some anti-symmetric terms that are being subtracted from paired main terms from any symmetric differential configurations for vector elements and/or matrix elements, the summation modules 2114A and 2114B can include a mechanism for some terms of the summation to be added after being inverted (equivalently, being subtracted from the non-inverted terms).
[0288]:
The summation modules 2114A and 2114B yield the following summation results, respectively, to complete the vector-matrix multiplication.
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 Regarding Claimed invention may not be obtained, notwithstanding that the Regarding Claimed invention is not identically disclosed as set forth in section 102, if the differences between the Regarding Claimed invention and the prior art are such that the Regarding Claimed invention as a whole would have been obvious before the effective filing date of the Regarding Claimed invention to a person having ordinary skill in the art to which the Regarding Claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-6, and 8-16 are rejected under 35 U.S.C. 103 as being unpatentable over
Jianhua Wu et.al (hereinafter Wu) US 2022/0179159 A1,
In view of ANAS SKALLI et.al (hereinafter SKALLI) Photonic neuromorphic computing using vertical cavity semiconductor lasers, Vol. 12, No. 6/1 Jun 2022/Optical Materials Express.
Claim 1:
A laser-based computing system, comprising: a two-dimensional photonic crystal surface emitting laser (PCSEL) array comprising a plurality of PCSEL emitters located in a first layer,
[0028]:
The beam-redirecting element can include a first surface that is configured to reflect the first optical beam into the first coupler, and a second surface that is configured to reflect the second optical beam into the second coupler.
[0194]:
FIG. 1 shows an example of a photonic computing system 100. The system 100 includes a photonic source 102 (e.g., a laser bar) attached to a submount 106, which is attached to a support structure 104 (e.g., a silicon-based substrate).
[BRI: Perhaps known to a POSITA that a beam-redirecting element can indeed incorporate a first surface that is a photonic crystal surface, and in fact, photonic crystal-based designs are actively being used for beam steering and redirection. Perhaps it is also known to a POSITA in semiconductor manufacturing, a silicon-based substrate is typically a single-crystal silicon wafer, which is a true crystal structure]
[0147]:
FIG. 14 is a schematic diagram of an example of an artificial neural network (ANN) computation system.
[0400]:
The internal operations of the ANN computation system 10100 will now be described. The optical processor 140 includes a laser unit 142, a modulator array 144, a detection unit 146, and an optical matrix multiplication (OMM) unit 150.
[0258]:
The following are additional examples of photonic computing systems that can incorporate the various techniques described in this specification, such as using the photonic integrated circuit as an interposer for other components, or the fabrication processes for assembling and aligning different components of the photonic computing system.
[0222]:
the capped conducting structures 1616 on the surface 1614 of the EIC 1600 and the capped conductive structures 1619 on the surface 1618 of the PIC 1602 can be arranged in the same pattern (e.g., a two-dimensional pattern) so that the capped conducting structures 1616 and 1619 are aligned with each other.
[0205]:
Electrical integrated circuit (EIC) chips can be included in the system 200 for performing various electronic control functions
[0218]:
FIGS. 16A-16E show an example of fabrication and assembly steps used to form a photonic computing system 1660 that includes an electronic integrated circuit (EIC) 1600 electrically coupled to a photonic integrated circuit (PIC) 1602 through electrical connection structures that provide electrical signal pathways.
- and a controller operatively connected to the plurality of PCSEL emitters, the controller configured to modulate phase and/or amplitude of a beam emitted by a PCSEL emitter of the plurality of PCSEL emitters.
[0009]:
The photonic source includes a third laser die on the substrate that can provide a third optical beam. The first laser die can be configured to provide the first optical beam from a first emitting location, the second laser die can be configured to provide the second optical beam from a second emitting location, and the third laser die can be configured to provide the third optical beam from a third emitting location. The first, second, and third emitting locations can be substantially aligned along a line.
[BRI: the EIC is a controller that is coupled to the PIC which consists of photon emitters]
[0194]:
FIG. 1 shows an example of a photonic computing system 100. The system 100 includes a photonic source 102 (e.g., a laser bar) attached to a submount 106, which is attached to a support structure 104 (e.g., a silicon-based substrate). The photonic source 102 comprises: a first laser module 108A providing a first optical beam 118A emitted from a first emitting location, and a second laser module 108B providing a second optical beam 118B emitted from a second emitting location. The optical beams are collectively referenced as 118. The system 100 includes a photonic integrated circuit 110 attached to the support structure 104. The photonic integrated circuit 110 comprises: a first waveguide and a first guided-mode resonance coupler 112A coupled to the first waveguide, and a second waveguide and a second guided-mode resonance coupler 112B coupled to the second waveguide. The guided-mode resonance couplers are collectively referenced as 112.
[0406]:
The light outputs of the laser unit 142 are coupled to the modulator array 144. The modulator array 144 is configured to receive the light inputs from the laser unit 142 and modulate the intensities of the received light inputs based on modulator control signals, which are electrical signals.
[0407]:
The DAC unit 130 generates, based on the first DAC control signal, the modulator control signals, which are analog signals suitable for driving the modulator array 144 and the OMM 150. The analog signals may be voltages or currents, for example, depending on the technology and design of the modulators of the array 144 and the OMM 150. The voltages may have an amplitude that ranges from, e.g., +0.1 V to ±10 V, and the current may have an amplitude that ranges from, e.g., 100 μA to 100 mA.
[0378]:
Referring to FIG. 40, in some implementations, homodyne detection can be used to obtain the phase and the amplitude of the modulated signal.
[0377]:
So, if the optical devices (e.g., the phase modulators in the optical amplitude modulators) are capable of operating at a symbol bandwidth B, they can be operated instead at a symbol bandwidth B/100, where each symbol value uses N=100 time slots.
Wu do not explicitly disclose:
each emitter oriented in a direction perpendicular to a plane formed by the first layer, wherein the plurality of PCSEL emitters form a preset pattern within the first layer;
However, SKALLI discloses:
each emitter oriented in a direction perpendicular to a plane formed by the first layer, wherein the plurality of PCSEL emitters form a preset pattern within the first layer;
[Abstract, Page 2395]:
Work along these lines includes (i) high performance hardware for artificial neurons, (ii) the efficient and scalable implementation of a neural network’s connections, and (iii) strategies to adjust network connections during the learning phase. In this review we provide an overview on vertical-cavity surface-emitting lasers (VCSELs) and how these high-performance electro-optical components either implement or are combined with additional photonic hardware to demonstrate points (i-iii),
[1, Page 2396]:
Vertical-cavity surface-emitting lasers (VCSELs) are one of the most prominent semiconductor lasers, with unique properties making them highly suitable for next generation PNN hardware. Figure 1(c) illustrates a VCSEL after fabrication and highlights how a VCSEL-based neuron would receive, transform and send information.
PNG
media_image1.png
707
1035
media_image1.png
Greyscale
[Abstract, Page 2395]:
as VCSEL arrays they are compatible with standard 2D photonic integration, but their emission vertical to the substrate makes them ideally suited for scalable integrated networks leveraging 3D photonic waveguides
[BRI: A Vertical-Cavity Surface-Emitting Laser (VCSEL) is a type of semiconductor laser diode in which the laser beam is emitted perpendicular to the top surface of the chip, unlike conventional edge-emitting lasers that emit from the side of the wafer. As a result, VCSEL is compatible with the standard 2D photonic integration PCSEL]
It would be obvious to one of ordinary skill in the art before the effective filing date of the present application to combine Wu and SKALLI.
Wu teaches a PCSEL.
SKALLI teaches Vertical-cavity surface-emitting lasers (VCSELs are a version of PCSEL and compatible with PCSEL that can be integrated into a neuromorphic computing and the prior art references PCSEL.
One of ordinary skills would be motivated to combine Wu and SKALLI involving VCSELs leverage their polarization properties to improve the information processing performance and speed (SKALLI [ 3, Page 2399]) and apply VCSEL to wide range range of tasks including spiking information storage (SKALLI [ 5.1, Page 2405]).
Claim 2:
Wu discloses:
- wherein the modulation comprises beam angle, coupling between emitters, and/or intensity.
[0269]:
the term “amplitude” may refer to the magnitude of the signal represented by the instantaneous or integrated power in the optical wave, or may also equivalently refer to the “electromagnetic field amplitude” of the optical wave. This is because the electromagnetic field amplitude has a well-defined relationship to the signal amplitude (e.g., by integrating an electromagnetic field intensity, which is proportional to the square of the electromagnetic field amplitude, over a transverse size of a guided mode or free-space beam to yield the instantaneous power). This leads to a relationship between modulation values, since a modulator that modulates the electromagnetic field amplitude by a particular value √{square root over (M)} can also be considered as modulating the power-based signal amplitude by a corresponding value M (since the optical power is proportional to the square of the electromagnetic field amplitude).
Claim 3:
Wu discloses:
further comprising a photodetector array located in a second layer comprised above the first layer, the photodetector array comprising a photodetector operatively connected to the controller,
[0215]:
In some implementations, the photonic computing system is configured to use the photonic integrated circuit (e.g., 224) to provide both an array of photonic computing elements that operate on optical signals carried by optical waveguides, and an interposer for transmitting electrical signals by conductor pathways to other portions of the system. This use of the photonic integrated circuit (e.g., 224) as an interposer can achieve a more compact system,
[0299]:
the optical waveguides can be routed within one layer of the substrate, or to avoid the waveguide crossings (and associated losses) that would be encountered in a single layer, waveguides can be routed within multiple layers of the substrate to allow more flexibility in routing paths that cross in two dimensions of the substrate but don't cross in a third dimension (of depth in the substrate)
[0251]:
The photonic integrated circuit can be configured to process input optical signals in various ways and is not limited to the examples described above. For example, the photonic integrated circuit can include input waveguides configured to carry input optical signals, and couplers coupled to corresponding input waveguides. The photonic integrated circuit can include operation photodetectors, in which each operation photodetector is configured to detect an optical signal derived from an operation (e.g., matrix operation, such as matrix multiplication operation) based on at least one input optical signal. The photonic integrated circuit also includes feedback photodetectors, in which each feedback photodetector is associated with an input waveguide
[0293]:
The current signals corresponding to the photocurrent generated by a pair of photodetectors 2212 and 2214 are combined at a junction 2216 to provide an output current signal whose amplitude corresponds to the difference between the amplitudes of the related optical signals.
[0273]:
In embodiments in which the summation is performed in the electrical domain, the summation module 1808 can be implemented using: (1) two or more input conductors that each carries an input current whose amplitude represents a result of one of the multiplication modules, and (2) at least one output conductor that carries a current that is the sum of the input currents. For example, this occurs if the conductors are wires that meet at a junction. Such a relationship can be understood, for example (without being bound by theory), based on Kirchhoff's current law, which states that current flowing into a junction is equal to current flowing out of the junction. For these embodiments, the signals 1810A and 1810B provided to the summation module 1808 are input currents, which can be produced by photodetectors that are part of the multiplication modules that generate a respective photocurrent whose amplitude is proportional to the power in a received optical signal. The summation module 1808 then provides the output current
i
s
u
m
. The instantaneous value of that output current, or the integrated value of that output current, can then be used to represent the quantitative value of the sum,
[0280]:
For example, the input vector elements v.sub.1 to v.sub.n are provided by n waveguides, and each input vector element is processed by one or more copying modules to provide m copies of the input vector element to m respective paths. There are m × n multiplication modules that each multiply by a different matrix element using optical amplitude modulation to produce an electrical or optical signal representing
M
i
j
.
v
j
(i=1 . . . m, j=1 . . . n).
[BRI: This advanced planar optical waveguide and integrated photodetector architecture (placed at the junctions to detect the signals) that can measure the difference of the amplitude which is the representation of a modulation]
- wherein the controller is further configured to: receive communication from the photodetector based on a detected signal, and perform a linear or non-linear beam control operation based at least in part on the communication received at the photodetector.
[0254]:
In some implementations, the photonic computing system includes two or more photonic integrated circuits mounted on an interposer. The interposer can include optical waveguides and optical couplers that provide optical signal paths to enable optical signals to be communicated between or among the two or more photonic integrated circuits
[0283]:
In FIG. 20B, the optical signals are detected in a common-terminal configuration where two photodiode detectors are connected to a common terminal 2032 (e.g., the inverting terminal) of an op-amp 2030. In this configuration, a current 2010 generated from a first photodiode detector 2012 and a current 2014 generated from a second photodiode detector 2016 combine at a junction 2018 among three conductors to produce a difference current 2020 between current 2010 and the current 2014,
[0260]:
computations can be performed using these operations, which represent a set of general linear operations from which a variety of computations can be performed, including but not limited to: vector-vector dot products, vector-vector element-wise multiplication, vector-scalar element wise multiplication, or matrix-matrix element-wise multiplication.
[0268]:
The optical signal encoded with the vector element
x
A
can be encoded using
different forms of amplitude modulation,
[0268]:
the power of a laser source can be modulated to have a particular power level from a predetermined set of multiple power levels,
[0268]:
The fraction of time that the power is at the “on” level corresponds to a particular energy level. Either of these particular values of power or energy can be mapped to a particular
value of the element
x
A
(using a linear or nonlinear mapping relationship).
Claim 4:
Wu discloses:
- wherein the system comprises a PCSEL-based computing architecture
[0028]:
The beam-redirecting element can include a first surface that is configured to reflect the first optical beam into the first coupler, and a second surface that is configured to reflect the second optical beam into the second coupler.
[0194]]:
FIG. 1 shows an example of a photonic computing system 100. The system 100 includes a photonic source 102 (e.g., a laser bar) attached to a submount 106, which is attached to a support structure 104 (e.g., a silicon-based substrate).
[BRI: Perhaps known to a POSITA that a beam-redirecting element can indeed incorporate a first surface that is a photonic crystal surface, and in fact, photonic crystal-based designs are actively being used for beam steering and redirection. Perhaps it is also known to a POSITA in semiconductor manufacturing, a silicon-based substrate is typically a single-crystal silicon wafer, which is a true crystal structure]
[Abstract]:
A method for assembling a photonic computing system includes attaching a photonic source to a support structure, and attaching a photonic integrated circuit to the support structure. The photonic source includes a first laser die on a substrate configured to provide a first optical beam, and a second laser die on the substrate configured to provide a second optical beam. The photonic integrated circuit includes a first waveguide and a first coupler coupled to the first waveguide, and a second waveguide and a second coupler coupled to the second waveguide. The method includes attaching a plurality of beam-shaping optical elements to the support structure, the substrate, or the photonic integrated circuit, in which the attaching includes aligning a first beam-shaping optical element during attachment so that the first optical beam is coupled to the first coupler, and aligning a second beam-shaping optical element during attachment so that the second optical beam is coupled to the second coupler.
[BRI: the above represents the architecture of photonic computing]
Claim 5:
Wu do not explicitly disclose:
- wherein the system is configured to create an optical neural network, to perform photonic computation, or to perform neuromorphic computation.
[Abstract]:
A method for assembling a photonic computing system includes attaching a photonic source to a support structure, and attaching a photonic integrated circuit to the support structure.
[0127]:
an artificial neural network computation system includes any of the apparatuses described above.
[0163]:
FIG. 28 is a schematic diagram of an example of a neural network computation system that uses a passive 2D optical matrix multiplication unit.
[0241]:
The artificial neural network computation system 1400 includes a controller 1404, a memory unit 1406, a DAC unit 1408, and an ADC unit 1410. The controller 1404 receives requests from a computer 1412 and sends the computation outputs to the computer 1412.
[0262]:
In some implementations, the optoelectronic computing system 1800 is configured to perform a computation on an array of input values that are encoded on respective optical signals provided by the optical ports or sources 1802A, 1802B, etc. For example, for various machine learning applications based on neural networks, the computation can implement vector-matrix multiplication (or vector-by-matrix multiplication) where an input vector is multiplied by a matrix to yield an output vector as a result.
Claim 6:
Wu discloses:
- wherein the system is configured to perform matrix multiplication.
[0270]:
The optical amplitude modulator used by the multiplication module to encode the matrix element
M
A
can operate by changing the amplitude of the optical signal (i.e., the power in the optical signal) using any of a variety of physical interactions.
[0270]:
For optical amplitude modulators that operate using interference (e.g., destructive and/or constructive interference) among optical waves that have traveled over different paths, coherent light sources such as lasers can be used. For optical amplitude modulators that operate using absorption, either coherent or non-coherent or low-coherence light sources
Claim 8:
Wu discloses:
- wherein the controller and PCSEL emitters are configured for coherent injection locking for controlling beam interference.
[0270]:
For optical amplitude modulators that operate using interference (e.g., destructive and/or constructive interference) among optical waves that have traveled over different paths, coherent light sources such as lasers can be used. For optical amplitude modulators that operate using absorption, either coherent or non-coherent or low-coherence light sources such as LEDs can be used.
[0407]:
with modulators that are based on PIN diode structures forward-biased to use carrier injection for modulating a refractive index of a portion of a waveguide that is guiding an optical wave being modulated,
[0292]:
The 1×2 optical amplitude modulator 2200 includes a 2×2 coupler 2206 that combines the optical waves from first and second input paths using optical interference or optical coupling in a particular manner to divert power into first and second output paths in different ratios, depending on the phase shift. For example, in a free-space interferometer, a phase shift of 0 degrees causes substantially all of the input power that was split between the two paths to constructively interfere to exit from one output path of a beam splitter implementing the coupler 2206, and a phase shift of 180 degrees causes substantially all of the input power that was split between the two paths constructively interfere to exit from the other output path of the beam splitter implementing the coupler 2206.
[0405]:
In some implementations, the laser unit 142 includes a single laser source and an optical power splitter. The single laser source is configured to generate laser light. The optical power splitter is configured to split the light generated by the laser source into N light outputs of substantially equal intensities and phase. By splitting a single laser output into multiple outputs, optical coherence of the multiple light outputs may be achieved. The single laser source may be, for example, a semiconductor laser diode, a vertical-cavity surface-emitting laser (VCSEL),
[0405]:
In some other implementations, a master-slave laser configuration may be used, where the slave lasers are injection locked by the master laser to have a stable phase relationship to the master laser.
[BRI: amplitude-modulated (AM) sideband injection locking can be considered a form of coherent injection locking when the interference between optical waves is used to control beam interference, and slave lasers are injection-locked by a master laser. Coherent injection locking relies on the phase relationship between the master and slave lasers. In AM sideband locking, the modulation sidebands carry phase information, so locking to these sidebands ensures that the slave lasers’ optical fields are coherently aligned with the master’s. This coherence allows for controlled beam interference.
Claim 9:
Wu discloses:
- wherein the detected signal comprises a summation of differential signals.
[0288]:
The system configuration 2110 also includes other modules arranged as shown in FIG. 21B to provide two different output electrical signals that represent an output vector that is the result of the vector-matrix multiplication performed by system 100. There are 16 different multiplication modules 1904 modulating different copies of the optical signals representing the input vector, and there are 16 different optical detection modules 1906 to provide electrical signals representing intermediate results of the computation. There are also two different summation modules 2114A and 2114B that compute the overall summation for each of the output electrical signals. In the figure, the signal lines electrically coupling the optical detection modules 1906 to the summation module 2114B are shown in dashed lines. Because each overall summation can include some anti-symmetric terms that are being subtracted from paired main terms from any symmetric differential configurations for vector elements and/or matrix elements, the summation modules 2114A and 2114B can include a mechanism for some terms of the summation to be added after being inverted (equivalently, being subtracted from the non-inverted terms).
[0288]:
The summation modules 2114A and 2114B yield the following summation results, respectively, to complete the vector-matrix multiplication.
Claim 10:
Wu do not explicitly disclose:
wherein the preset pattern of PCSEL emitters comprises at least one defect or irregularity.
However, SKALLI discloses:
wherein the preset pattern of PCSEL emitters comprises at least one defect or irregularity.
[6, Page 2407]:
The novel computing concepts discussed in this review rely crucially on vertically emitting lasers. VCSELs emit normal to the chip surface, can be controlled electrically, show high-speed dynamics and are energy efficient [82] and are much more compact than edge emitting lasers,
[6.1, Page 2407]:
The fabrication of VCSELs requires multiple nanoprocessing steps. It starts with the epitaxial growth of a planar microresonator structure by means of molecular beam epitaxy (MBE) or metal-organic chemical vapour deposition (MOCVD).
[6.1, Page 2407]:
the central cavity includes at least one thin AlGaAs layer with high Al-content (>90%), which is later oxidized and acts as current window and leads to lateral light confinement governing the emission beam profile. The lateral nanoprocessing of VCSEL devices starts with the patterning of circular mesa structures with diameters in the range of 20- 30 µm by means of UV lithography and plasma etching
[Abstract, Page 2395]:
as VCSEL arrays they are compatible with standard 2D photonic integration, but their emission vertical to the substrate makes them ideally suited for scalable integrated networks leveraging 3D photonic waveguides.
[BRI: Perhaps know to a POSITA that a lateral light confinement in semiconductor emitters (such as laser diodes) refers to the design or physical structure that controls how the optical field spreads in the horizontal plane. This confinement is typically achieved through lateral carrier confinement (e.g., double-oxide layers) and optical field confinement (e.g., waveguide or microcavity structures). The resulting emission beam profile is a direct consequence of how these confinements shape the optical output. The inventor’s intention of vertical cavity lasers, provide a risk of lateral shift]
It would be obvious to one of ordinary skill in the art before the effective filing date of the present application to combine Wu and SKALLI.
Wu teaches a PCSEL.
SKALLI teaches Vertical-cavity surface-emitting lasers (VCSELs are a version of PCSEL and compatible with PCSEL that can be integrated into a neuromorphic computing and the prior art references PCSEL.
One of ordinary skills would be motivated to combine Wu and SKALLI involving VCSELs leverage their polarization properties to improve the information processing performance and speed (SKALLI [ 3, Page 2399]) and apply VCSEL to wide range range of tasks including spiking information storage (SKALLI [ 5.1, Page 2405]).
Claim 11:
Wu discloses:
A laser-based computing system,
[0147]:
FIG. 14 is a schematic diagram of an example of an artificial neural network (ANN) computation system.
comprising: a two-dimensional photonic crystal surface emitting laser (PCSEL) array
[0028]:
The beam-redirecting element can include a first surface that is configured to reflect the first optical beam into the first coupler, and a second surface that is configured to reflect the second optical beam into the second coupler.
[0194]]:
FIG. 1 shows an example of a photonic computing system 100. The system 100 includes a photonic source 102 (e.g., a laser bar) attached to a submount 106, which is attached to a support structure 104 (e.g., a silicon-based substrate).
[BRI: Perhaps known to a POSITA that a beam-redirecting element can indeed incorporate a first surface that is a photonic crystal surface, and in fact, photonic crystal-based designs are actively being used for beam steering and redirection. Perhaps it is also known to a POSITA in semiconductor manufacturing, a silicon-based substrate is typically a single-crystal silicon wafer, which is a true crystal structure]
[0009]:
The photonic source includes a third laser die on the substrate that can provide a third optical beam. The first laser die can be configured to provide the first optical beam from a first emitting location, the second laser die can be configured to provide the second optical beam from a second emitting location, and the third laser die can be configured to provide the third optical beam from a third emitting location. The first, second, and third emitting locations can be substantially aligned along a line.
[BRI: the EIC is a controller that is coupled to the PIC which consists of photon emitters]
[0194]:
FIG. 1 shows an example of a photonic computing system 100. The system 100 includes a photonic source 102 (e.g., a laser bar) attached to a submount 106, which is attached to a support structure 104 (e.g., a silicon-based substrate). The photonic source 102 comprises: a first laser module 108A providing a first optical beam 118A emitted from a first emitting location, and a second laser module 108B providing a second optical beam 118B emitted from a second emitting location. The optical beams are collectively referenced as 118. The system 100 includes a photonic integrated circuit 110 attached to the support structure 104. The photonic integrated circuit 110 comprises: a first waveguide and a first guided-mode resonance coupler 112A coupled to the first waveguide, and a second waveguide and a second guided-mode resonance coupler 112B coupled to the second waveguide. The guided-mode resonance couplers are collectively referenced as 112.
[0406]:
The light outputs of the laser unit 142 are coupled to the modulator array 144. The modulator array 144 is configured to receive the light inputs from the laser unit 142 and modulate the intensities of the received light inputs based on modulator control signals, which are electrical signals.
[0407]:
The DAC unit 130 generates, based on the first DAC control signal, the modulator control signals, which are analog signals suitable for driving the modulator array 144 and the OMM 150. The analog signals may be voltages or currents, for example, depending on the technology and design of the modulators of the array 144 and the OMM 150. The voltages may have an amplitude that ranges from, e.g., +0.1 V to ±10 V, and the current may have an amplitude that ranges from, e.g., 100 μA to 100 mA.
[0378]:
Referring to FIG. 40, in some implementations, homodyne detection can be used to obtain the phase and the amplitude of the modulated signal.
[0377]:
So, if the optical devices (e.g., the phase modulators in the optical amplitude modulators) are capable of operating at a symbol bandwidth B, they can be operated instead at a symbol bandwidth B/100, where each symbol value uses N=100 time slots.
a photodetector array located in a second layer comprised above the first layer;
and a controller operatively connected to the plurality of PCSEL emitters and the photodetector array, the controller configured to modulate a plurality of beams emitted by the plurality of PCSEL emitters.
[0215]:
In some implementations, the photonic computing system is configured to use the photonic integrated circuit (e.g., 224) to provide both an array of photonic computing elements that operate on optical signals carried by optical waveguides, and an interposer for transmitting electrical signals by conductor pathways to other portions of the system. This use of the photonic integrated circuit (e.g., 224) as an interposer can achieve a more compact system,
[0299]:
the optical waveguides can be routed within one layer of the substrate, or to avoid the waveguide crossings (and associated losses) that would be encountered in a single layer, waveguides can be routed within multiple layers of the substrate to allow more flexibility in routing paths that cross in two dimensions of the substrate but don't cross in a third dimension (of depth in the substrate)
[0251]:
The photonic integrated circuit can be configured to process input optical signals in various ways and is not limited to the examples described above. For example, the photonic integrated circuit can include input waveguides configured to carry input optical signals, and couplers coupled to corresponding input waveguides. The photonic integrated circuit can include operation photodetectors, in which each operation photodetector is configured to detect an optical signal derived from an operation (e.g., matrix operation, such as matrix multiplication operation) based on at least one input optical signal. The photonic integrated circuit also includes feedback photodetectors, in which each feedback photodetector is associated with an input waveguide
[0293]:
The current signals corresponding to the photocurrent generated by a pair of photodetectors 2212 and 2214 are combined at a junction 2216 to provide an output current signal whose amplitude corresponds to the difference between the amplitudes of the related optical signals.
[0273]:
In embodiments in which the summation is performed in the electrical domain, the summation module 1808 can be implemented using: (1) two or more input conductors that each carries an input current whose amplitude represents a result of one of the multiplication modules, and (2) at least one output conductor that carries a current that is the sum of the input currents. For example, this occurs if the conductors are wires that meet at a junction. Such a relationship can be understood, for example (without being bound by theory), based on Kirchhoff's current law, which states that current flowing into a junction is equal to current flowing out of the junction. For these embodiments, the signals 1810A and 1810B provided to the summation module 1808 are input currents, which can be produced by photodetectors that are part of the multiplication modules that generate a respective photocurrent whose amplitude is proportional to the power in a received optical signal. The summation module 1808 then provides the output current
i
s
u
m
. The instantaneous value of that output current, or the integrated value of that output current, can then be used to represent the quantitative value of the sum,
[0280]:
For example, the input vector elements v.sub.1 to v.sub.n are provided by n waveguides, and each input vector element is processed by one or more copying modules to provide m copies of the input vector element to m respective paths. There are m × n multiplication modules that each multiply by a different matrix element using optical amplitude modulation to produce an electrical or optical signal representing
M
i
j
.
v
j
(i=1 . . . m, j=1 . . . n).
[BRI: This advanced planar optical waveguide and integrated photodetector architecture (placed at the junctions to detect the signals) that can measure the difference of the amplitude which is the representation of a modulation]
Wu do not explicitly disclose:
each emitter oriented in a direction perpendicular to a plane formed by the first layer, wherein the plurality of PCSEL emitters form a preset pattern within the first layer;
However, SKALLI discloses:
each emitter oriented in a direction perpendicular to a plane formed by the first layer, wherein the plurality of PCSEL emitters form a preset pattern within the first layer;
[Abstract, Page 2395]:
Work along these lines includes (i) high performance hardware for artificial neurons, (ii) the efficient and scalable implementation of a neural network’s connections, and (iii) strategies to adjust network connections during the learning phase. In this review we provide an overview on vertical-cavity surface-emitting lasers (VCSELs) and how these high-performance electro-optical components either implement or are combined with additional photonic hardware to demonstrate points (i-iii),
[1, Page 2396]:
Vertical-cavity surface-emitting lasers (VCSELs) are one of the most prominent semiconductor lasers, with unique properties making them highly suitable for next generation PNN hardware. Figure 1(c) illustrates a VCSEL after fabrication and highlights how a VCSEL-based neuron would receive, transform and send information.
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[Abstract, Page 2395]:
as VCSEL arrays they are compatible with standard 2D photonic integration, but their emission vertical to the substrate makes them ideally suited for scalable integrated networks leveraging 3D photonic waveguides
[BRI: A Vertical-Cavity Surface-Emitting Laser (VCSEL) is a type of semiconductor laser diode in which the laser beam is emitted perpendicular to the top surface of the chip, unlike conventional edge-emitting lasers that emit from the side of the wafer. As a result, VCSEL is compatible with the standard 2D photonic integration PCSEL]
It would be obvious to one of ordinary skill in the art before the effective filing date of the present application to combine Wu and SKALLI.
Wu teaches a PCSEL.
SKALLI teaches Vertical-cavity surface-emitting lasers (VCSELs are a version of PCSEL and compatible with PCSEL that can be integrated into a neuromorphic computing and the prior art references PCSEL.
One of ordinary skills would be motivated to combine Wu and SKALLI involving VCSELs leverage their polarization properties to improve the information processing performance and speed (SKALLI [ 3, Page 2399]) and apply VCSEL to wide range range of tasks including spiking information storage (SKALLI [ 5.1, Page 2405]).
Claim 12:
Wu discloses:
- wherein the modulation comprises beam angle, coupling between emitters, and/or intensity.
[0269]:
the term “amplitude” may refer to the magnitude of the signal represented by the instantaneous or integrated power in the optical wave, or may also equivalently refer to the “electromagnetic field amplitude” of the optical wave. This is because the electromagnetic field amplitude has a well-defined relationship to the signal amplitude (e.g., by integrating an electromagnetic field intensity, which is proportional to the square of the electromagnetic field amplitude, over a transverse size of a guided mode or free-space beam to yield the instantaneous power). This leads to a relationship between modulation values, since a modulator that modulates the electromagnetic field amplitude by a particular value √{square root over (M)} can also be considered as modulating the power-based signal amplitude by a corresponding value M (since the optical power is proportional to the square of the electromagnetic field amplitude).
Claim 13:
Wu discloses:
- wherein the photodetector array comprises a photodetector operatively connected to the controller
[0215]:
In some implementations, the photonic computing system is configured to use the photonic integrated circuit (e.g., 224) to provide both an array of photonic computing elements that operate on optical signals carried by optical waveguides, and an interposer for transmitting electrical signals by conductor pathways to other portions of the system. This use of the photonic integrated circuit (e.g., 224) as an interposer can achieve a more compact system,
[0299]:
the optical waveguides can be routed within one layer of the substrate, or to avoid the waveguide crossings (and associated losses) that would be encountered in a single layer, waveguides can be routed within multiple layers of the substrate to allow more flexibility in routing paths that cross in two dimensions of the substrate but don't cross in a third dimension (of depth in the substrate)
[0251]:
The photonic integrated circuit can be configured to process input optical signals in various ways and is not limited to the examples described above. For example, the photonic integrated circuit can include input waveguides configured to carry input optical signals, and couplers coupled to corresponding input waveguides. The photonic integrated circuit can include operation photodetectors, in which each operation photodetector is configured to detect an optical signal derived from an operation (e.g., matrix operation, such as matrix multiplication operation) based on at least one input optical signal. The photonic integrated circuit also includes feedback photodetectors, in which each feedback photodetector is associated with an input waveguide
- wherein the controller is further configured to: receive communication from the photodetector based on a detected signal, and perform a linear or non-linear beam control operation based at least in part on the communication received at the photodetector.
[0254]:
In some implementations, the photonic computing system includes two or more photonic integrated circuits mounted on an interposer. The interposer can include optical waveguides and optical couplers that provide optical signal paths to enable optical signals to be communicated between or among the two or more photonic integrated circuits
[0283]:
In FIG. 20B, the optical signals are detected in a common-terminal configuration where two photodiode detectors are connected to a common terminal 2032 (e.g., the inverting terminal) of an op-amp 2030. In this configuration, a current 2010 generated from a first photodiode detector 2012 and a current 2014 generated from a second photodiode detector 2016 combine at a junction 2018 among three conductors to produce a difference current 2020 between current 2010 and the current 2014,
[0260]:
computations can be performed using these operations, which represent a set of general linear operations from which a variety of computations can be performed, including but not limited to: vector-vector dot products, vector-vector element-wise multiplication, vector-scalar element wise multiplication, or matrix-matrix element-wise multiplication.
[0268]:
The optical signal encoded with the vector element
x
A
can be encoded using
different forms of amplitude modulation,
[0268]:
the power of a laser source can be modulated to have a particular power level from a predetermined set of multiple power levels,
[0268]:
The fraction of time that the power is at the “on” level corresponds to a particular energy level. Either of these particular values of power or energy can be mapped to a particular
value of the element
x
A
(using a linear or nonlinear mapping relationship).
Claim 14:
Wu discloses:
- wherein the system comprises a PCSEL-based computing architecture
[0028]:
The beam-redirecting element can include a first surface that is configured to reflect the first optical beam into the first coupler, and a second surface that is configured to reflect the second optical beam into the second coupler.
[0194]]:
FIG. 1 shows an example of a photonic computing system 100. The system 100 includes a photonic source 102 (e.g., a laser bar) attached to a submount 106, which is attached to a support structure 104 (e.g., a silicon-based substrate).
[BRI: Perhaps known to a POSITA that a beam-redirecting element can indeed incorporate a first surface that is a photonic crystal surface, and in fact, photonic crystal-based designs are actively being used for beam steering and redirection. Perhaps it is also known to a POSITA in semiconductor manufacturing, a silicon-based substrate is typically a single-crystal silicon wafer, which is a true crystal structure]
[Abstract]:
A method for assembling a photonic computing system includes attaching a photonic source to a support structure, and attaching a photonic integrated circuit to the support structure. The photonic source includes a first laser die on a substrate configured to provide a first optical beam, and a second laser die on the substrate configured to provide a second optical beam. The photonic integrated circuit includes a first waveguide and a first coupler coupled to the first waveguide, and a second waveguide and a second coupler coupled to the second waveguide. The method includes attaching a plurality of beam-shaping optical elements to the support structure, the substrate, or the photonic integrated circuit, in which the attaching includes aligning a first beam-shaping optical element during attachment so that the first optical beam is coupled to the first coupler, and aligning a second beam-shaping optical element during attachment so that the second optical beam is coupled to the second coupler.
[BRI: the above represents the architecture of photonic computing]
Claim 15:
Wu do not explicitly disclose:
- wherein the system is configured to create an optical neural network, to perform photonic computation, or to perform neuromorphic computation.
[Abstract]:
A method for assembling a photonic computing system includes attaching a photonic source to a support structure, and attaching a photonic integrated circuit to the support structure.
[0127]:
an artificial neural network computation system includes any of the apparatuses described above.
[0163]:
FIG. 28 is a schematic diagram of an example of a neural network computation system that uses a passive 2D optical matrix multiplication unit.
[0241]:
The artificial neural network computation system 1400 includes a controller 1404, a memory unit 1406, a DAC unit 1408, and an ADC unit 1410. The controller 1404 receives requests from a computer 1412 and sends the computation outputs to the computer 1412.
[0262]:
In some implementations, the optoelectronic computing system 1800 is configured to perform a computation on an array of input values that are encoded on respective optical signals provided by the optical ports or sources 1802A, 1802B, etc. For example, for various machine learning applications based on neural networks, the computation can implement vector-matrix multiplication (or vector-by-matrix multiplication) where an input vector is multiplied by a matrix to yield an output vector as a result.
Claim 16:
Wu discloses:
- wherein the detected signal comprises a summation of differential signals.
[0288]:
The system configuration 2110 also includes other modules arranged as shown in FIG. 21B to provide two different output electrical signals that represent an output vector that is the result of the vector-matrix multiplication performed by system 100. There are 16 different multiplication modules 1904 modulating different copies of the optical signals representing the input vector, and there are 16 different optical detection modules 1906 to provide electrical signals representing intermediate results of the computation. There are also two different summation modules 2114A and 2114B that compute the overall summation for each of the output electrical signals. In the figure, the signal lines electrically coupling the optical detection modules 1906 to the summation module 2114B are shown in dashed lines. Because each overall summation can include some anti-symmetric terms that are being subtracted from paired main terms from any symmetric differential configurations for vector elements and/or matrix elements, the summation modules 2114A and 2114B can include a mechanism for some terms of the summation to be added after being inverted (equivalently, being subtracted from the non-inverted terms).
[0288]:
The summation modules 2114A and 2114B yield the following summation results, respectively, to complete the vector-matrix multiplication.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over
Jianhua Wu et.al (hereinafter Wu) US 2022/0179159 A1,
In view of ANAS SKALLI et.al (hereinafter SKALLI) Photonic neuromorphic computing using vertical cavity semiconductor lasers, Vol. 12, No. 6/1 Jun 2022/Optical Materials Express.
further in view of Yong Lee et.al (hereinafter Lee) US 5115442 A.
Claim 7:
Wu and SKALLI do not explicitly disclose:
wherein the PCSEL emitters comprise a laterally-confined lasing mode.
However, Lee discloses:
wherein the PCSEL emitters comprise a laterally-confined lasing mode.
[Col 1, lines 13-25]:
The vertical cavity, surface emitting laser structure (SEL), is emerging as a promising solution to the recognized need for inexpensive, reliable laser structures. Its two-dimensional nature, with its very small active gain region volume translates into the low lasing threshold currents which relieve the problem of heat dissipation. While the SEL is certainly of interest, as a discrete device, it is regarded by many as a significant potential breakthrough in terms of integration--both all-optical and opto-electronic. Contemplated uses include optical switching/computing, photonic interconnection, high/low power laser sources, image processing, neural networks, etc,
[Col 1, lines 33-36]:
As the dimension of the active region is reduced in the lasing direction (to yield lowest lasing threshold values), increased cavity reflectance is needed to accommodate the correspondingly reduced per-pass gain.
[Col 3, lines 15-17]:
FIG. 4, on coordinates of output power and pump current, shows typical lasing threshold and lasing characteristics of a laser of the invention.
[Col 5, lines 39-40]:
Implantation/annealing conditions were not optimized in terms of minimum lasing threshold,
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[Col 5, lines 41-51]:
It is useful to consider both the nature and magnitude of implant damage. Two considerations are of primary consequence to the inventive teaching--1) the lateral damage gradient at the buried peak damage level which must both result in the gradient essential to the funnel-like current path to properly bias the active gain material while leaving the material within the laser pillar substantially undamaged and 2) the vertical damage gradient from the buried peak to the surface on which the ions are first incident in order, retain sufficient conductivity for desired lasing threshold.
[BRI: the threshold provides the confinement for the lasing mode]
It would be obvious to one of ordinary skill in the art before the effective filing date of the present application to combine Wu, SKALLI and Lee.
Wu teaches a PCSEL.
SKALLI teaches Vertical-cavity surface-emitting lasers (VCSELs are a version of PCSEL and compatible with PCSEL that can be integrated into a neuromorphic computing and the prior art references PCSEL.
Lee teaches lateral confinement in the lasing mode.
One of ordinary skills would be motivated to combine Wu, SKALLI and Lee that can provide optimized conditions resulting in a steeper lateral gradient to retain substantially unimpaired conductivity at the center of the pillar (Lee [ Col 6, lines 39-42]).
Conclusion
Any inquiry concerning this communication or earlier communications from the
examiner should be directed to TIRUMALE KRISHNASWAMY RAMESH whose telephone number is (571)272-4605. The examiner can normally be reached by phone.
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/TIRUMALE K RAMESH/Examiner, Art Unit 2121
/Li B. Zhen/Supervisory Patent Examiner, Art Unit 2121
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