Degradation of Ga1−xAlxAs visible diode lasers

Abstract
It is shown that Ga1−xAlxAs visible lasers degrade faster at shorter lasing wavelengths. The degradation in the wavelength region below 730 nm can mainly be attributed to the rapid formation of macroscopic defects in the active region. A notable improvement in life is obtained for these shorter wavelength lasers by Te‐doping of the active layer. On the other hand, degradation at above 740‐nm results from enhanced facet oxidation due to high AlAs mole fractions in the layers. Facet coatings using SiO2 films effectively suppress facet oxidation. As a result, room‐temperature extrapolated lives exceeding 10 000 h are achieved in the wavelength region above 740 nm.