Free-Space Optical Interconnect System Using Polarisation Rotating Modulator Arrays

An optical circuit was designed and built to facilitate the testing of a free-space optical interconnect. Details of the optical design are presented. The interconnect was based on a hybrid CMOS/GaAs chip which had a 16 x 16 array of detectors on a 250 mu m pitch interlaced with a 16 x 16 array of modulators. The optomechanics enabled two such chips, bonded to printed circuit boards, to be mounted, positioned and aligned relative to each other. The operating wavelength of the devices was 827 nm. The optical system worked successfully and alignment could be achieved across the array with ease and high precision.