We report what is believed to be the first observation of lasing of an opti
cally pumped thin CdS film formed by laser ablation on glass. Laser action
is observed at room temperature, and the emission peak is at 501 nm. X-ray
diffraction shows that the polycrystalline films are of wurtzite structure
and have (002) preferred orientation. Fabry-Perot laser modes are spaced 16
nm apart, indicating a cavity length of 2.9 mu m. The cavity is formed by
consistently self-formed microcavities within the hexagonal lattice. (C) 19
99 Optical Society of America OCIS codes: 140.3580, 140.5560, 310.6860, 140
.3390.