The first blue-green laser diodes were demonstrated in our laboratorie
s in early April 1991 using wide band gap II-VI semiconductors. Since
then, devices with emission wavelengths from 508 to 535 nm have been o
btained in the pulsed mode at room temperature with threshold current
densities about 1000 A/cm2. Continuous wave devices have also been ope
rated at 80 K emitting more than 3 mW/facet. These diodes are separate
confinement devices with single CdxZn1-xSe strained quantum wells wit
hin ZnSe p-n junctions. Optical confinement is accomplished by surroun
ding the ZnSe guide with ZnS0.07Se0.93 cladding layers. Characteristic
s of these devices and the issues standing in the way of commercializi
ng II-VI LEDs and diode lasers are discussed.