Simple method for examining sulphur passivation of facets in InGaAs–AlGaAs (λ=0.98 μm) laser diodes

The effect of (NH4)2Sx treatment of the facet of InGaAs/AlGaAs ridge waveguide (RW) laser diodes on the nonradiative current and catastrophic optical damage (COD) level is reported. Using the power–voltage–current (P–V–I) characteristics of the electroluminescence at low injection levels, changes in the density of surface states at the laser facets are described.