title: Noise immune cavity enhanced optical heterodyne velocity modulation spectroscopy.
abstract: The novel technique of cavity enhanced velocity modulation spectroscopy has recently been demonstrated as the first general absorption technique that allows for sub-Doppler spectroscopy of molecular ions while retaining ion-neutral discrimination. The previous experimental setup has been further improved with the addition of heterodyne detection in a NICE-OHMS setup. This improves the sensitivity by a factor of 50 while retaining sub-Doppler resolution and ion-neutral discrimination. Calibration was done with an optical frequency comb, and line centers for several N(2)(+) lines have been determined to within an accuracy of 300 kHz.
authors: Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors: Brian M
authors: BM
authors: Siller
authors: Michael W
authors: MW
authors: Porambo
authors: Andrew A
authors: AA
authors: Mills
authors: Benjamin J
authors: BJ
authors: McCall
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D055096:Optical Devices; D012031:Refractometry / Q000295:instrumentation*; D013057:Spectrum Analysis / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*