High-power laser diodes emitting 808 nm. I. Thermal mechanisms limiting output optical power

The paper reviews thermal mechanisms limiting the output optical power of laser diodes. Though the review is focused on the laser emitting light at 808 nm, the mechanisms considered are of general character and work in a wide range of the emission wavelengths. The catastrophic optical damage of the resonator mirrors and sublinearity of the light-current characteristics are two general mechanisms of the output power limitation. The paper discusses the nature and specific features of the catastrophic optical damage. The sublinearity of the light-current characteristics is, in turn, controlled by a number of factors. The most important among them are the rise of the threshold current and degradation of the differential quantum efficiency of the laser diodes with temperature, as well as the carrier leakage from the heterostructure followed by their non-radiation recombination at the ohmic contacts. The literature review is illustrated by the results of simulations of the laser structures operation.