Hyperspectral imaging of gases with a continuous-wave pump-enhanced optical parametric oscillator

We demonstrate a system for the active real-time hyperspectral imaging of gases using a combination of a compact, pump-enhanced, continuous-wave optical parametric oscillator as an all-solid-state mid-infrared source of coherent radiation and an electro-mechanical polygonal imager. The wide spectral coverage and high spectral resolution characteristics of this source means that the system is capable of being selectively tuned into the absorption features of a wide variety of gaseous species. As an example we show how the largest absorption coefficient exhibited by methane at 3057.7 cm(-1) can be accessed (amongst others) and gas plumes imaged in concentrations as low as 30 ppm. m using a parametric oscillator based on periodically-poled RbTiOAsO4 (PP-RTA). (C) 2004 Optical Society of America.