A new approach to detecting a weak photoacoustic signal in a gas medium is described. Instead of a gas-filled resonant acoustic cavity, the sound energy is accumulated in a high- <i>Q</i> crystal element. Feasibility experiments utilizing a quartz-watch tuning fork demonstrate a sensitivity of 1.2×10<sup>-7</sup> cm<sup>-1</sup> W/√Hz . Potential further developments and applications of this technique are discussed.
© 2002 Optical Society of America
A. A. Kosterev, Yu.A. Bakhirkin, R. F. Curl, and F. K. Tittel, "Quartz-enhanced photoacoustic spectroscopy," Opt. Lett. 27, 1902-1904 (2002)