Performance of vertically coupled backside fiber-optic interconnections to GaAs

A vertical coupling technique suited for dense fiber-optic interconnection of two-dimensional device arrays in GaAs has recently been developed. It uses cavities etched in the backside of the wafer to align each fiber to a diaphragm photodetector (DPD) fabricated on the front-surface epitaxial layers. Operation of the fiber-pigtailed DPDs is described. Enhanced optoelectronic performance due to the backside approach as well as the capability of addressing interconnect arrays with approximately 10 fibers/mm/sup 2/ is reported.