Compact, packaged free-space optical interconnect

We present a packaged free-space optical interconnect, based on the Optical Transpose Interconnect System, which is designed to provide a bi-directional interconnection between two optoelectronic chips each of which contains thirty-two modulators and detectors. The optical system consists of two polarization-selective computer generated holograms, which combine a 4×8 lenslet array for illumination of the modulators and a 2×2 lenslet array for interconnection, allowing for a very simple and compact optical system. In addition to the holograms, the only other components necessary to complete the optical system are a polarizing beam splitter, two quarter-wave retardation plates, and a spacer. All of the optics are aligned and packaged into a single unit that is remarkably compact: 12.7×32.2 mm, weighing only 8.3 g.