Sol-gel silica laser tunable in the blue.

Doped and undoped silica slabs were fabricated through the use of the sol-gel technique. Extended UV transmission was observed for HCl-catalyzed sol-gel silica. Under transverse pumping with a XeCl laser, narrow-linewidth (<0.9-nm) laser oscillation from silica slabs doped with coumarin 460 (C460) was achieved in a grating-resonator cavity configured in the grazing-indicence geometry. Tuning of the C460-doped silica laser extended from 468 to 494 nm. The conversion efficiency of the narrow-linewidth blue laser was 5.5%.