Abstract

We have obtained cw operation of a color center laser based on what we have tentatively identified as the ${({\mathit{F}}_2^{+})}_{\mathit{A}}$ defect in additively-colored potassium-doped NaCl. The laser tunes smoothly from 1.46 to 1.76 μm when pumped with a cw Nd:YAG laser operating at 1.06 μm. To date the best cw power obtained from the laser has been 210 mW. Operation for periods up to 10 hours has been monitored with no observable fading or decrease in output power. Similar to lasers utilizing other known ${({\mathit{F}}_2^{+})}_{\mathit{A}}$ centers,^1,2 the laser crystal must be exposed to an auxiliary light during laser operation to continually reionize the ${({\mathit{F}}_2^{+})}_{\mathit{A}}$ centers. The 365 nm line of a Hg arc lamp is a convenient source of this auxiliary light. Once additively colored, the crystals may be stored at room temperature with no degradation.

© 1985 Optical Society of America