Abstract

A practical diode-pumped tunable chromium solid state laser would be highly valued for its use in a variety of scientific, medical, industrial, and military applications. Efforts to date to develop such lasers have exclusively used “red” AlGaInP quaternary diodes because they emit near the peak of the lowest-lying chromium ion pump band (~640 nm). Today, red diodes are relatively lacking in efficiency, power, availability, and low-cost compared to well-developed AlGaAs diodes emiting in the 750–850 nm region. But, because AlGaAs diodes emit in the longwave wing of the chromium pump band, they have not been regarded as being useful for pumping chromium lasers. The practicality of such a laser, which is based on a two-level, Stokes-shifted energy-level system, depends critically on the exact pumpband lineshape, the Stokes-shift energy, the ability to heavily dope the crystal with chromium without significant deleterious effects, and the absence of parasitic loss in the laser spectral region. We present spectroscopic, kinetic, and laser data that confirms that longwave (752 nm) wing pumping in Cr:LiSAF is practical.

© 1991 Optical Society of America