A high-resolution cw spectrometer based on difference frequency generation (DFG) in a 20-mm-long AgGaS2 crystal pumped by two stabilized single-frequency cw dye–Ti:sapphire lasers is described. Experiments performed with a Rhodamine 6G and DCM dye laser combination pumped by a 20-W argon laser are reported. Infrared radiation is generated from 7 to 9 μm with an ultranarrow linewidth (<0.5 MHz) and an output power of 1 μW by making use of 90° type I phase matching. The performance of the DFG laser spectrometer is evaluated by using a portion of the v2 band of NH3 near 1177 cm−1.
© 1992 Optical Society of America
P. Canarelli, Z. Benko, R. Curl, and F. K. Tittel, "Continuous-wave infrared laser spectrometer based on difference frequency generation in AgGaS2 for high-resolution spectroscopy," J. Opt. Soc. Am. B 9, 197-202 (1992)