Abstract: A method of performing a multiplication operation in the optical domain using a device (100) comprising: an optical waveguide (101), and a modulating element (102) that is optically coupled to the optical waveguide (101), the modulating element (102) modifying a transmission, reflection or absorption characteristic of the waveguide (101) dependant on its state, wherein the state of the modulating element (102) is adjustable by a write signal (103). The method comprises: encoding a first value to the write signal (103), using the write signal (103) to map the first value to a state of the modulating element (102); encoding a second value to a read signal (104); producing an output signal intensity as the transmitted or reflected read signal, wherein the product of the first value and the second value is encoded in the output signal intensity.

Abstract: A co-processor for performing a matrix multiplication of an input matrix with a data matrix in one step may be provided. The co-processor receives input signals for the input matrix as optical signals. A plurality of photonic memory elements is arranged at crossing points of an optical waveguide crossbar array. The plurality of memory elements is configured to store values of the data matrix. Input signals are connected to input lines of the optical waveguide crossbar array. Output lines of the optical waveguide crossbar array represent a dot-product between a respective column of the optical waveguide crossbar array and the received input signals, and values of elements of the input matrix to be multiplied with the data matrix correspond to light intensities received at input lines of the respective photonic memory elements. Additionally, different wavelengths are used for each column of the input matrix optical signals.

Abstract: A co-processor for performing a matrix multiplication of an input matrix with a data matrix in one step may be provided. The co-processor receives input signals for the input matrix as optical signals. A plurality of photonic memory elements is arranged at crossing points of an optical waveguide crossbar array. The plurality of memory elements is configured to store values of the data matrix. Input signals are connected to input lines of the optical waveguide crossbar array. Output lines of the optical waveguide crossbar array represent a dot-product between a respective column of the optical waveguide crossbar array and the received input signals, and values of elements of the input matrix to be multiplied with the data matrix correspond to light intensities received at input lines of the respective photonic memory elements. Additionally, different wavelengths are used for each column of the input matrix optical signals.

Abstract: A method of performing a multiplication operation in the optical domain using a device (100) comprising: an optical waveguide (101), and a modulating element (102) that is optically coupled to the optical waveguide (101), the modulating element (102) modifying a transmission, reflection or absorption characteristic of the waveguide (101) dependant on its state, wherein the state of the modulating element (102) is adjustable by a write signal (103). The method comprises: encoding a first value to the write signal (103), using the write signal (103) to map the first value to a state of the modulating element (102); encoding a second value to a read signal (104); producing an output signal intensity as the transmitted or reflected read signal, wherein the product of the first value and the second value is encoded in the output signal intensity.