In-network optical inference

A method of inference processing, the method comprising:

• transmitting a first data packet containing an input vector to a layer of neurons in an artificial neural network from a client to a programmable packet switch comprising a programmable packet processing chip and an optical computing unit;
• concatenating, by the programmable packet processing chip, a weight vector corresponding to the layer of neurons with the first data packet;
• transmitting the first data packet and the weight vector from the programmable packet processing chip to the optical computing unit;
• computing a product of the input vector and the weight vector with the optical computing unit;
• transmitting a second data packet containing the product of the input vector and the weight vector from the optical computing unit to the programmable packet processing chip;
• and
• applying a nonlinear activation function to the product with the programmable packet processing chip,
• wherein computing the product of the input vector and the weight vector comprises:
• modulating, with a first modulator, an optical pulse with a waveform proportional to the input vector;
• modulating, with a second modulator in optical communication with the first modulator, the optical pulse with a waveform proportional to the weight vector;
• and
• detecting the optical pulse with a photodetector in optical communication with the second modulator.

A programmable packet switch comprising:

• a programmable packet processing chip to concatenate a first data packet representing an input vector to a first layer of neurons of an artificial neural network with a first weight vector corresponding to the first layer of neurons;
• and
• an optical processor, operably coupled to the programmable packet processing chip, to receive the first data packet and the first weight vector from the programmable packet processing chip, to compute a product of the input vector and the first weight vector, and to transmit the product of the input vector and the first weight vector to the programmable packet processing chip as a second data packet,
• wherein the programmable packet processing chip is configured to remove source and/or destination metadata from the first data packet before transmitting the first data packet and the first weight vector to the optical processor.

A method of inference processing, the method comprising:

• receiving a packet with a header comprising source/destination metadata and a payload comprising an input to a deep neural network (DNN);
• removing the source/destination metadata from the header;
• adding a weight vector corresponding to a first layer of the DNN to the header;
• transmitting the packet to an optical processor comprising a first modulator, a second modulator in series with the first modulator, and a photodetector;
• converting the input to the DNN into a first analog waveform;
• converting the weight vector into a second analog waveform;
• modulating, by the first modulator, an amplitude of an optical beam with the first analog waveform;
• modulating, by the second modulator, the amplitude of the optical beam with the second analog waveform;
• transducing, by the photodetector, the optical beam into an electrical signal with an amplitude representing a product of the input to the DNN and the weight vector;
• and
• performing a nonlinear activation on the electrical signal to produce an output of the first layer of the DNN.