Stability of ZnSe-Passivated Laser Facets Cleaved in Air and in Ultra-High Vacuum

Catastrophic optical mirror damage (COMD) is one of the main failure mechanisms limiting the reliability of GaAs based laser diodes. Here, we compare the facet stability of ZnSe-passivated ridge-waveguide lasers (RWLs) that are cleaved in air and subsequently cleaned using atomic hydrogen with RWLs that are cleaved in ultra-high vacuum. RWLs cleaved in ultra-high vacuum show a superior performance and reach power densities up to 58 MW/cm
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under extended continuous wave operation at 1064 nm. This is attributed to the reduction of defects at the interface between ZnSe and the cleaved facet as evidenced by transmission electron microscopy and X-ray diffraction.