High-Speed Diagnostic of Temperature and Intensity Variation on Diode-Laser Facets

In this STTR project, Science Research Laboratory (SRL) and Boston University Photonics Center (BU Photonics) will develop a revolutionary optical technology for detecting localized increases in temperature on time scales ranging from nanoseconds to microseconds. By appropriately responding to instabilities in laser diodes (LDs), SRL has demonstrated a 10X increase in their lifetime. Localized diode heating is a critical factor limiting the lifetime of LDs; such heating causes optical and electrical instabilities that damage the emitters and lead to their failure. These instabilities lead to catastrophic optical damage (COD), in which a dramatic temperature increase causes melting in the vicinity of the output facet. In Phase 1 we will obtain electrical and optical data that presage emitter failure. This data will enable SRL to design intelligent electronics that will help protect laser diodes and increase their performance and lifetime. In Phase 2, we will (1) fabricate intelligent fault-protection electronics that are based on the results of Phase 1; (2) demonstrate the improvement in lifetime and performance obtained by protecting; and (3) deliver a prototype of the protection circuit to a facility of DARPA’s choice for additional testing and verification.