Visible Semiconductor Lasers

Short-wavelength semiconductor lasers will potentially lead to major improvements in the performance of optical data storage systems. The various approaches to making visible semiconductor lasers are reviewed, including II-VI and III-V compound semiconductor lasers, and frequency-doubled infrared lasers. Although it is anticipated that diode lasers constructed from II-VI compounds will become important in the future, high-performance diode lasers of AlGaInP, a high-bandgap III-V alloy, are presently available. Lasing wavelength is 650nm<2.<680nm, and typical threshold current densities are 1-3 kλ/cm2. Recent advances in the growth of quantum well device structures have resulted in significant performance improvements.