ABSTRACT
Selecting from but a handful of commercially available laser and nonlinear optical crystals, laser designers have produced an impressive array of lasers able to perform a wide range of scientific, commercial, industrial, and military applications. Laser design possibilities were enormously expanded with the development in the late-1980s of efficient and powerful semiconductor laser diodes as pump sources for solid state lasers. The development of semiconductor laser diode pump sources throughout the 650–2000nm spectral band that are efficient, powerful and narrowband, has revolutionised the field of lasers based on rare earth and transition-metal doped solid state materials. The nonradiative decay of electronic levels in laser crystals also strongly influences the performance of solid state lasers. The “energy-gap” law, elucidated by empirical studies performed by Riseberg and Moos and by Riseberg and Weber, is especially useful in the screening of possible novel diode-pumped laser schemes.
