3.3-mu m microcavity light emitter for gas detection

A room-temperature resonant-cavity light source emitting at 3.327 mu m is p resented. It combines a CdHgTe light-emitting layer, grown by molecular bea m epitaxy, and two evaporated YF3-ZnS Bragg mirrors. The emitter is optical ly pumped by a commercial low-power GaAs laser diode. Compared with an unpr ocessed sample, this microcavity device shows a drastic (10-fold) linewidth reduction, a 3.3-fold intensity increase at 3.327 mu m, and a 2.4-fold ang ular-spread decrease. The emitted optical power is 15 mu W, and the device is used as a light source in a basic gas-detection setup. Measurements of a butane-propane mixture in the 1 to 5 x 10(-3) bar range with a 5-cm-long s ingle-path gas cell are demonstrated. (C) 2000 Optical Society of America.