Blue‐Green ZnSe Laser Diodes for Optoelectronics. Present State at Würzburg University

A review is given on the research activities at Würzburg University in the field of blue‐green emitting ZnSe laser diodes. Of great importance for both the structural and electrical properties is the possibility to grow a GaAs buffer layer on the GaAs substrate prior to the II–VI growth. Pulsed room temperature lasing with a duty cycle up to 17% is obtained using quaternary ZnMgSSe cladding layers, ternary ZnSSe waveguides, and a single CdZnSe quantum well. Important issues for long‐term stability of such laser diodes like growth start, p‐type doping, and ohmic contacts are discussed.