Screening techniques for high power GaAsP/AlGaAs/GaAs semiconductor diode lasers

We report on novel evaluation methodology of high-power diode lasers that potentially will increase the reliability level of these devices. The study is carried out for wide-stripe, 808 nm diode lasers with low fast-axis beam divergence that base on a double-barrier single quantum well separate confinement heterostructure. The diodes are assembled in standard packages with base diameter s = 9 mm. Degradation of diode lasers is a result of the interaction between internal and external factors. Thus, insight into degradation mechanisms is only possible with a complex characterization of the devices. In our analysis we involved standard measurements such as current-voltage, light-current characterizations, as well as advanced methods such as high-resolution thermography. The latter one allows for investigations of thermal properties of diode lasers including fast temperature profiling and defect recognition. We discuss the usefulness of above techniques for screening purposes. Finally we present results of reliability tests of the diode lasers. A correlation between initial tests and lifetest results is shown.