We describe a broadly tunable, ew optical parametric oscillator (OPO) based
on periodically poled lithium niobate. The OPO can be tuned over a broad r
egion in the mid IR (2900-3100 cm(-1)) covering the important C-H stretch r
egion while a high spectral resolution (<0.1 cm(-1)) is maintained. The OPO
is the light source for a field-portable photoacoustic spectrometer for ga
s-phase monitoring of volatile organic compounds. (C) 2001 Optical Society
of America.