Device characteristics of green II–VI semiconductor lasers

We have studied the device properties of blue-green II–VI lasers pertaining to the issues of thermal effects, leakage current and lateral waveguiding. Improved heat sinking by epi-down mounting was found to double the device lifetime. Leakage, mainly consisting of drift currents, is caused by the low p-type dopability of quaternary II–VI materials. This worsens on the lasing wavelength shortens. Although thermal index guiding was found to reduce the astigmatism of gain-guided lasers, index guiding by a built-in refractive index profile is necessary to obtain astigmatism values suitable for optical recording.