Output performance of a dye-doped sol-gel silica laser in the near UV

Visibly transparent near-UV dye (Exalite 377E)-doped silica in the form of parallelepiped were prepared by the low-temperature sol-gel process. The laser output performance of dye-doped sol-gel silica samples pumped by a short pulse (1 ns) N-2 laser at 337 nm was reported. With a grating as the wavelength selection element, the laser was tuned from 367 to 387 nm with a laser linewidth of 2 nm. Using a resonator cavity consisting of two flat mirrors, the sol-gel laser showed a slope efficiency of 34.7% and a pump energy threshold of 20 mu J. The variation of sol-gel laser energy output as a function of the number of pulses under repetitive N-2 laser excitation was investigated. The laser output energy decreased initially with the number of shots. The output energy recovered to its original intensity after a ten minute interruption in pumping. In this way, the dye-doped samples showed no signs of long term degradation after being irradiated at 337 nm for tens of thousand shots. (C) 1996 American Institute of Physics.