Continuous-wave laser action using F+ centers in CaO crystals is reported in the blue range of the visible spectrum. These centers may be pumped by using either Ar+ or N2 laser lines. The laser is tunable in the range 357–420 nm with an output power of ≃15 mW at the band center for an input power of 100 mW.
© 1981 Optical Society of America
B. Henderson, "Tunable visible lasers using F+ centers in oxides," Opt. Lett. 6, 437-439 (1981)