In situ measurement of misalignment errors in free-space optical interconnects

A nonobtrusive technique for measuring misalignment errors in multistage free-space optical interconnects is proposed. The technique makes use of dedicated microoptics to relay higher order dedicated alignment beams generated by an optical power supply onto alignment detectors located on the periphery of a smart pixel chip. An implementation of this technique for measuring lateral (x-y) misalignment error in a multistage optical backplane demonstrator is then presented. Performance parameters are analyzed and future directions such as photonic extensions to electronic boundary scan standards are suggested.