We combine highly sensitive intracavity absorption spectroscopy in a multimode laser with external photoacoustic detection, providing high detectivity. Photoacoustic measurements of the intracavity iodine concentration in a Rhodamine 6G laser are compared with simultaneous spectral recordings. They demonstrate slightly improved overall sensitivity and a greatly enhanced dynamic range of 5 orders of magnitude that may be shifted along the absolute scale of absorber density.
© 1999 Optical Society of America
Torsten J. Latz, Gabriele Weirauch, Valery M. Baev, and Peter E. Toschek, "External Photoacoustic Detection of a Trace Vapor Inside a Multimode Laser," Appl. Opt. 38, 2625-2629 (1999)