Cavity ringdown laser absorption spectroscopy with a 1 kHz mid-infrared periodically poled lithium niobate optical parametric generator optical parametric amplifier

A cavity ringdown spectrometer is described that employs a novel mid-infrared light source based on periodically poled lithium niobate. The source generates tunable light using the three-step process of optical parametric generation, spectral filtering, and optical parametric amplification. Its use allows for improvements over previous pulsed ringdown measurements including the ability to acquire data rapidly (at 1 kHz) over broad spectral regions tin principle, over the entire 2220-7690 cm(-1) PPLN transparency window) with narrow linewidth (less than or equal to 0.08 cm(-1)). Data are presented that demonstrate performance and support its eventual use in a trace gas sensor. (C) 1999 Elsevier Science B.V. All rights reserved.