Internal-loss-limited maximum operating temperature and characteristic temperature of quantum dot laser

Carrier-density-dependent internal optical loss sets an upper limit for operating temperatures and considerably reduces the characteristic temperature of a quantum dot laser. Such internal loss also constrains the shallowest potential well depth and the smallest tolerable size of a quantum dot at which the lasing can be attained. At the maximum operating temperature or when any parameter of the structure is equal to its critical tolerable value, the characteristic temperature drops to zero.