Status and Challenges of Waveguide Blue Lasers

Abstract

The advantages of short-wavelength lasers for magneto-optic recording have long been recognized. Recording at ~1 Gbit/in2 was demonstrated several years ago using an Argon-ion laser at 488 nm [1]. More recently, recording at 2.4 Gbit/in2 has been demonstrated using a 488-nm Argon-ion laser and a frequency-doubled GaAlAs laser diode at 429 nm [2]. However, both Argon-ion lasers and frequency-doubled diode lasers are relatively bulky and expensive compared to the infrared diode lasers used in commercial magneto-optic recording systems. Hence, a great deal of research continues to focus on the development of small, efficient, low-cost blue sources with powers suitable for optical recording. Although the advent of blue-green semiconductor laser diodes based on II-VI materials has attracted much attention, sustained, reliable room-temperature operation at powers suitable for recording applications has not been demonstrated, and a recent study of defect formation in such lasers suggests that development of a source suitable for recording applications may be very difficult [3].