An optical pickup using a blue-green laser diode to read high-density disk

Since Haase et al. reported in 1991 semiconductor pulsed blue-green laser diode operation at 77 K based on ZnCdSe-ZnSSe, a number of researchers have investigated the II-VI laser diode. In 1991 Sony developed the ZnMgSSe cladding layer, and in 1996 demonstrated over 100-hour, continuous wave operation of II-VI laser diode at room temperature. We describe in this paper an optical pickup using this II-VI laser diode for reading high-density disks and its readout characteristics.