Vertical cavity surface emitting laser-based cryogenic optical link technology

Cryogenic focal plane array (FPA) technology is widely used in both military and commercial applications. Three key factors that must be addressed to meet the future needs of FPA applications and improve their technology are (1) reduction of power dissipation in the FPA; (2) electrical and thermal isolation of the FPA assembly; and (3) simplicity of packaging. Conventional electronic data link packaging, which transmits data received by the FPA detector array to a warm external electronic processing module, does not address the above issues. Therefore, Physical Optics Corporation (POC) has investigated, for the first time, a vertical cavity surface emitting laser (VCSEL) based cryogenic optical link technology. This approach not only addressed the low-cost smart cryogenic FPA sensor, but also was the most viable and practical approach among other optical link technologies. This paper presents our major work in this project, which include (1) design, fabrication, and packaging of cryogenic VCSEL array and VCSEL array transmitter chip; (2) modification of a commercially available dewar to include the optical readout portion; (3) design, fabrication of optic fiber array link subsystem and assemble of entire system; and (4) preliminary test and demonstration.