Abstract

Strontium aluminum pentafluoride crystals doped with chromium, SrAlF₅:Cr have been shown to produce continuously tunable pi-polarized laser emission from 825 nm to 1010 nm with krypton ion laser pumping.^1-4 In the more recent experiments a slope efficiency of 15% was obtained for conversion of absorbed pump radiation at 647 nm to the output beam at 910 nm, with approximately 1% output coupling from the SrAlF₅:Cr laser resonator.³ The observed efficiency was considerably less than the quantum defect limited efficiency of 71%, and led to speculation that there was a high level of loss in the material. To check this hypothesis a series of experiments has been carried out in which the magnitude of the linear loss coefficient and the gain per unit pump power have been determined as a function of wavelength from 890 nm to 970 nm.

© 1986 Optical Society of America