Degradation phenomena in high-power single quantum well algaas ridge lasers

Degradation studies with over 235, 000 device hours have been performed on single quantum well AlGaAs lasers with uncoated and half-wavelength Al2O3 coated facets at stress levels ranging from below threshold up to optical power densities of 23 mW per µm facet width. The effectiveness of facet protection has been investigated with respect to gradual degradation and catastrophic failures. Lasers with facet protection showed gradual degradation rates as low as 0.18%/kh at power densities of 10 mW/µm, and lifetime improvement factors up to 27, 000 at 16 mW/µm compared to uncoated facets. © 1990 The Japan Society of Applied Physics.