Threshold current as acceleration parameter for degradation of 980 nm pump lasers

To experimentally demonstrate reliability beyond levels achieved previously, as required for applications like submarine, one would like to have higher degradation acceleration than available just from temperature and optical power. In particular, this would also be of importance for lot and technology validation. From earlier stress-test experiments, we have evidence that threshold current could be an additional accelerating factor. In this paper we describe the acceleration of the current-degradation rate observed with laser operation at higher threshold-current (I_th) levels. Higher-I _th devices have been obtained either through selection within a standard population or through modification of the front-mirror reflectivity. The devices used in the experimental work are standard 980 nm E2 lasers, i.e. 750 μm long MBE-grown SQW AlGaInAs lasers with a 4 μm wide ridge etched into the top p-cladding