Mechanism of catastrophic degradation in 1.3-μm V-grooved substrate buried-heterostructure lasers with the application of large pulsed currents

Abstract

Catastrophic degradation of V-grooved substrate buried-heterostructure InGaAsP/InP lasers (λ=1.3 μm), by large pulsed currents, has been investigated using scanning electron microscopy, etching technique, energy dispersive x-ray spectroscopy, and spatially resolved photoluminescence topography. After the degradation, the diode stops lasing and becomes ohmic. These are associated with the following phenomena: (i) facet erosion inside or outside the stripe region; (ii) penetration of the electrode-metals into the epitaxial layer. These phenomena are presumably caused by the abrupt passage of large current along the facet or by local heating at the contact region outside the stripe region. Catastrophic optical damage, which frequently occurs in GaAlAs/GaAs double-heterostructure lasers, is not observed in any part of the degraded diodes.