We demonstrate a technique for gas phase spectroscopy and sensing by detecting changes in compliance voltage of an external cavity quantum cascade laser due to intracavity absorption. The technique is characterized and used to measure the absorption spectrum of water vapor and Freon-134a.
© 2012 Optical Society of America
Lasers and Laser Optics
Original Manuscript: March 12, 2012
Revised Manuscript: May 3, 2012
Manuscript Accepted: May 14, 2012
Published: June 26, 2012
Mark C. Phillips and Matthew S. Taubman, "Intracavity sensing via compliance voltage in an external cavity quantum cascade laser," Opt. Lett. 37, 2664-2666 (2012)