Observation of degradation recovery in 1.3-μm GaInAsP-InP inverted-rib semiconductor lasers

This paper reports some effects arising from interrupted lifetest of 1.3-μm GaInAsP-InP inverted-rib laser diodes. This unconventional lifetest method involves constant power biasing at 4 mW/facet and 8 mW/facet, respectively, at 50°C, followed by a period during which the devices were left unbiased at room temperature (off-test period). At the end of the off-test period, the devices were put back on constant power biasing at 50°C. A pronounced reduction in the threshold current, current for 4 mW/facet and 8 mW/facet were observed during the initial part of the off-test period. Similar improvements were also seen in the external quantum efficiency with corresponding variations also occurring in the device series resistance, characteristic temperature, threshold junction voltage, and the emission spectra linewidth. Such recovery effects have so far been observed to occur only in the GaInAsP-InP inverted-rib devices