Abstract: The invention relates to an apparatus and a method for characterizing a microlithographic mask. According to one aspect, an apparatus according to the invention comprises at least one light source which emits coherent light, an illumination optical unit which produces a diffraction-limited light spot on the mask from the coherent light of the at least one light source, a scanning device, by use of which it is possible to implement a scanning movement of the diffraction-limited light spot relative to the mask, a sensor unit, and an evaluation unit for evaluating the light that is incident on the sensor unit and has come from the mask, an output coupling element for coupling out a portion of the coherent light emitted by the at least one light source, and an intensity sensor for capturing the intensity of this output coupled portion.

Abstract: An optical matrix multiplication unit for an optoelectronic system can be used to form an artificial neural network, having N input waveguides, M output waveguides and a plurality of matrix multiplication unit cells for signal processing of optical signals of one each of the N input waveguides and for transferring the processed signals into one each of the M output waveguides, wherein each of the matrix multiplication unit cells is allocated to one of the input waveguides and one of the output waveguides and undertakes a unique allocation between said two allocated waveguides. Each of the matrix multiplication unit cells has, for signal processing and signal transfer, a directional coupler, having an electrooptical modulator for transmission control of the directional coupler, interconnected between the allocated input waveguide and the allocated output waveguide.

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.