Abstract: In a multi-chip module and method, the multi-chip module includes a carrier; a multimode optical waveguide formed on and/or in the carrier; a first and second chip disposed on the carrier and coupled to the multimode optical waveguide; wherein the first chip is configured to transmit light beams into the multimode optical waveguide; the multimode optical waveguide is configured to generate mixed light beams that are an at least partial superposition of the light beams; the second chip is configured to receive the mixed light beams from the multimode optical waveguide; and the second chip is configured to store a representation of the received mixed light beams as a transmission signature and/or as a cryptographic key in a memory associated with the second chip, and/or compare the representation of the received mixed light beams with a target representation stored in the memory associated with the second chip.

Abstract: A receiving apparatus and method for determining transmission characteristics of an optical waveguide in which the receiving apparatus includes a waveguide interface for receiving a mixed light beam having a plurality of modes from a multi-mode optical waveguide and for receiving a blended shifted light beam from the multimode optical waveguide, wherein the mixed light beam has an associated phase for each mode of the plurality of modes, and wherein the mixed shifted light beam has an associated shifted phase for each mode of the plurality of modes; and one or more processors for determining mode information for the intermixed light beam and shifted mode information for the intermixed shifted light beam using a trained neural network and for determining, for each mode of the plurality of modes, the respective associated phase using the intermixed shifted light beam.

Abstract: A receiving apparatus and method for determining transmission characteristics of an optical waveguide in which the receiving apparatus includes a waveguide interface for receiving a mixed light beam having a plurality of modes from a multi-mode optical waveguide and for receiving a blended shifted light beam from the multimode optical waveguide, wherein the mixed light beam has an associated phase for each mode of the plurality of modes, and wherein the mixed shifted light beam has an associated shifted phase for each mode of the plurality of modes; and one or more processors for determining mode information for the intermixed light beam and shifted mode information for the intermixed shifted light beam using a trained neural network and for determining, for each mode of the plurality of modes, the respective associated phase using the intermixed shifted light beam.