Abstract

Eye-safe lasers are required for a variety of commercial and military applications. At present the two most commonly used approaches for achieving eye-safe operation are flashlamp pumped Er:Glass and Raman shifted Nd:Host lasers. Flashlamp pumped Er:Glass lasers suffer from a rather poor efficiency while Raman shifted Nd:Host lasers must incorporate a cell containing a highly compressed flammable gas. In this research we investigated the use of Nd:Host lasers operating in the range 1.047-1.064 μm to directly pump Er doped phosphate glass activated with the ion Yb. Yb displays a broad, strong absorption band with a peak absorption at 970 nm but extending well into the 1.06 μm region.

The results of these experiments demonstrate that Nd:YLF is a near ideal Nd pump source for Er:Glass, and furthermore that the use of diode-pumping sources operating near the 970 nm Yb absorption band can, in an optimized system, lead to over an order of magnitude increase in the wallplug efficiency when compared to current methods. Diode-pumped Er:Glass lasers are scalable and can be implemented in normal mode, Q-switched, CW, and mode-locked configurations.

© 1990 Optical Society of America