Photonic processing systems and methods
Aspects relate to a photonic processing system, a photonic processor, and a method of performing matrix-vector multiplication. An optical encoder may encode an input vector into a first plurality of optical signals. A photonic processor may receive the first plurality of optical signals; perform a plurality of operations on the first plurality of optical signals, the plurality of operations implementing a matrix multiplication of the input vector by a matrix; and output a second plurality of optical signals representing an output vector. An optical receiver may detect the second plurality of optical signals and output an electrical digital representation of the output vector.
1. A photonic processing system comprising:
an optical power tree configured to receive an optical source signal and to produce a plurality of optical reference signals;
an optical encoder configured to produce a plurality of input optical signals by optically encoding the plurality of optical reference signals with a plurality of input numeric values;
a photonic processor configured to produce a plurality of output optical signals by performing a matrix-matrix multiplication or matrix-vector multiplication based on the plurality of input optical signals;
an optical receiver configured to produce a plurality of output numeric values based on the plurality of output optical signals; and
a controller configured to perform a first iteration comprising:
receiving an input bit string,
producing, using the input bit string, input analog signals representing the plurality of input numeric values, and providing the input analog signals to the optical encoder,
programming the photonic processor based on a weight matrix,
receiving output analog signals representing the plurality of output numeric values from the optical receiver, and
producing, using the output numeric values, an output bit string; and
wherein the controller is further configured to perform a second iteration comprising:
producing, using the output bit string, further input analog signals representing a further plurality of input numeric values, and providing the further input analog signals to the optical encoder.
2. The photonic processor of claim 1 , wherein the optical power tree is configured to distribute a power of the optical source signal substantially evenly across the plurality of optical reference signals.
3. The photonic processing system of claim 1 , wherein the optical power tree comprises an array of optical beam splitters.
4. The photonic processing system of claim 3 , wherein the array of optical beam splitters is arranged in layers including at least first, second and third layers, wherein the first layer comprises N beam splitters, the second layer comprises 2N beam splitters and the third layer comprises 4N beam splitters, wherein N is equal to or greater than 1.
5. The photonic processing system of claim 1 , wherein the optical receiver comprises a plurality of optical homodyne detectors configured to produce the plurality of output numeric values based on the plurality of output optical signals.
6. The photonic processing system of claim 5 , wherein at least one of the plurality of optical homodyne detectors is configured to produce one of the plurality of output numeric values by combing one of the plurality of output optical signals with the optical source signal.
7. The photonic processing system of claim 1 , wherein the optical encoder and the photonic processor are disposed on a common substrate.
8. The photonic processing system of claim 1 , wherein the optical encoder and the photonic processor are interconnected to each other via silicon photonic waveguides.
9. The photonic processing system of claim 1 , further comprising a vertical-cavity surface emitting laser (VCSEL) configured to provide the optical source signal to the optical power tree.
10. The photonic processing system of claim 1 , wherein the optical encoder is disposed on a chip, and wherein the VCSEL is surface-bonded to the chip.
11. The photonic processing system of claim 1 , wherein the optical power tree comprises a multimode interferometer (MMI).
12. The photonic processing system of claim 1 , further comprising a plurality of optical amplitude adjustment modulators configured to modulate the plurality of optical reference signals.
13. The photonic processing system of claim 1 , wherein the photonic processor is configured to perform the matrix-matrix multiplication or matrix-vector multiplication using matrix decomposition.