Parallel architectures for nanophotonic computing

A nanophotonic computing system, comprising:

• an optical source;
• a stack of photonic layers composed of metalenses and intervening specialized modulators, wherein each metalens comprises a flat lens metastructure composed of subwavelength scale elements, and wherein each specialized modulator comprises a modulator metastructure composed of subwavelength scale elements;
• and
• an optical detector array;
• wherein the nanophotonic computing system is configured to channel light emanating from the optical source through the stack of photonic layers and onto the optical detector array to facilitate optical computing operations.

A universal optical waveform transformer, comprising:

• a metaphonic mode multiplexer, which facilitates arbitrary beamforming;
• a metaphonic mode demultiplexer, which facilitates arbitrary decomposition;
• and
• a unitary photonic matrix element, coupled between the metaphonic mode multiplexer and the metaphonic mode demultiplexer, which facilitates converting any input spatial mode to any output spatial mode.

An orbital angular momentum (OAM) state multiplexer/demultiplexer, comprising:

• a circular arrangement of apertures;
• a set of phase-matched waveguides coupled to the circular arrangement of apertures;
• and
• a star coupler coupled to the set of phase-matched waveguides.