Surface-normal 4x4 nonblocking wavelength-selective optical crossbar interconnect using polymer-based volume holograms and substrate-guided waves

We present a 4x4 surface-normal wavelength-selective nonblocking crossbar using polymer-based volume holograms and substrate-guided waves. A prototype device is demonstrated using the center wavelengths of 750, 780, 810, and 840 nm, The employment of wavelength-division multiplexer and of address coding reduce the required 16 wavelengths to four while maintaining the 4 x 4 interconnects. Diffraction efficiencies of 85%, 83%, 79%, and 82% are experimentally confirmed for randomly polarized light at 750, 780,810, and 840 nm, respectively. The measured crosstalk is less than -24 dB.