Two-tone frequency-modulation spectroscopy in off-axis cavity
Authors: Malara P., Witinski M. F., Gagliardi G., De Natale P.
Autors Affiliation: Consiglio Nazionale delle Ricerche—Istituto Nazionale di Ottica, via campi flegrei 34, Pozzuoli (NA), Italy; Eos Photonics, Inc., Cambridge, Massachusetts 02138, USA; School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
Abstract: As opposed to a conventional optical resonator, an off-axis-aligned cavity is able to transmit without distortion radiation modulated at a frequency even far above the cavity bandpass. This allows us to implement a simple spectroscopic technique that combines the cavity path-length enhancement of integrated cavity output spectroscopy (ICOS) and the noise reduction associated with radio-frequency modulation (FM). An FM-ICOS spectrometer is demonstrated for the first time using a two-tone modulation technique. The performance is compared to the traditional ICOS by examining the acetylene absorption at 1543.77 nm. A signal-to-noise ratio improvement by a factor 3.5 is found with our proof-of-concept setup. Larger improvements are expected in a more optimized setup. (C) 2013 Optical Society of America
Journal/Review: OPTICS LETTERS
Volume: 38 (22) Pages from: 4625 to: 4628
KeyWords: Band pass; Frequency-modulation spectroscopy; Integrated cavity output spectroscopies; Modulation techniques; Path length; Proof of concept; Radio-frequency modulation; Spectroscopic technique, Molecular spectroscopy; Noise abatement; Spectrometers; Frequency modulationDOI: 10.1364/OL.38.004625Citations: 2data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2019-10-20References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here