Abstract

The retroreflective properties of a corner cube can substantially reduce the need for alignment accuracy in optical chip-to-chip interconnections. We specially designed corner cubes with dihedral angles slightly different from right angles, so that the reflected beams are split into two-, four-, five-, or six-spot image patterns for a point source, depending on the dihedral angles. Arbitrary spot pat terns may be obtained with a corner-cube design by mean sofa ray-tracing and iteration procedure. We have shown that under the paraxial condition, these corner cubes are not sensitive to variations of the incident angles. When the source is laterally shifted by some misalignment, the spot pattern will follow the source and will suffer a second-order infinitesimal deformation. Corner-cube reflectors can be made in the form of micro-tetrahedral prisms with dimensions of several microns that will allow a high fanout number. We propose a geometric arrangement for positioning the sources and detectors on the chip and have demonstrated a 4-cube network in a space-invariant interconnection system using two corner cubes, each having a six-spot image pattern.

© 1990 Optical Society of America