ABSTRACT
Images of the electron beam induced currents taken in a scanning electron microscope from the laser front facet of 980 nm pump laser diodes give indications for facet degradation already in an early stage. Changes in the equilevel lines of the of the electron beam induced current signal in the light output region reveal a decreased minority carrier diffusion length LD and/or an increased surface recombination velocity. Transmission electron microscopy of the facet front region of laser diodes with AlGaAs waveguide layers shows migration of the main layer components (Al, In) in the light output region due to facet degradation. However, laser diodes with InGaP waveguide layers operating under the same conditions show no defect contrast at all.
