Single-frequency tunable VECSELs emitting at 2.3 /spl mu/m for spectroscopy application

Vertical External-Cavity Surface-Emitting Lasers (VECSEL) exhibit narrow linewidth single-frequency operation and wide mode-hope-free tuning range, particularly well adapted for trace gas spectroscopy application, especially in the 2-2.5 /spl mu/m atmospheric transparency window (CH4, NH3, CO2...). VECSELs over come beam quality limitations of laser diodes and power restrictions of microcavity VCSELS.