Abstract: In optical interconnect systems, information may be encoded in different wavelengths of light in an optical signal in a wavelength division multiplexing (WDM) scheme. The inventors have recognized and appreciated that the data rate of an optical interconnect system may be doubled by employing a polarization multiplexing scheme, where some information is encoded in an optical signal having a first polarization state and other information is encoded in an optical signal having a second, orthogonal polarization state as the different polarizations will act independently while propagating along a fiber. Accordingly, described herein are systems and techniques for optical interconnect systems employing polarization multiplexing.

Abstract: Methods and apparatus for training a matrix-based differentiable program using a photonics-based processor. The matrix-based differentiable program includes at least one matrix-valued variable associated with a matrix of values in a Euclidean vector space. The method comprises configuring components of the photonics-based processor to represent the matrix of values as an angular representation, processing, using the components of the photonics-based processor, training data to compute an error vector, determining in parallel, at least some gradients of parameters of the angular representation, wherein the determining is based on the error vector and a current input training vector, and updating the matrix of values by updating the angular representation based on the determined gradients.