Thermal Behavior of High Power GaAs-based Laser Diodes in Vacuum Environment

Since 980nm GaAs-based laser diodes are now implemented in space missions, there is a huge need to study their thermal behavior under vacuum in order to evaluate their reliability. Then spatially resolved temperature variations have been evaluated by thermoreflectance on the front facet under atmospheric and vacuum conditions, and for two different unpumped windows (UPW) lengths. We show that, in all cases, vacuum induces a front facet temperature variation increase of the laser diodes, making them more sensitive to a catastrophic optical damage (COD).