Off-Axis Cavity Ring Down Spectroscopy Based on a Continuous-Wave Optical Parametric Oscillator

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Infrared/Raman

Scientific paper

Continuous-wave cavity ring down spectroscopy (cw-CRDS) is a sensitive absorption technique for trace gas analysis. Although it is highly sensitivity and relatively fast, ring down repetition rate and spectral resolution are limited by the cavity free spectral range (FSR). Normally, the injected beam is mode matched to the lowest transverse electro-magnetic mode (TEM00) of the cavity. Light is coupled into the cavity only when standing wave condition is fulfilled. Scanning of the laser without variation of the cavity length leads to transmission comb where recorded ring down times are separated in frequency by the FSR. Recently Romanini et. al. reported an off-axis (OA) CRDS spectrometer operating in the 766 nm region where the FSR of the cavity was reduced by N = 4 times from the original. In this re-entrant condition the cavity length is chosen to provide degeneracy of transverse modes. If the injection is adequately off-axis the beam returns to the starting point after N round trips. This divides the FSR to N group of degenerated modes which are equally frequency-spaced. We present an OA-CRDS spectrometer (N = 4) based on a continuous-wave optical parametric oscillator (cw-OPO) operating in the mid-infrared region (2.75 - 3.45 μm). The measurement of formaldehyde (H_2CO) using an OA-CRDS spectrometer will be presented.
J. Courtois, A. K. Mohamed and D. Romanini Opt. Express 18, (5), 1 March 2010.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Off-Axis Cavity Ring Down Spectroscopy Based on a Continuous-Wave Optical Parametric Oscillator does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Off-Axis Cavity Ring Down Spectroscopy Based on a Continuous-Wave Optical Parametric Oscillator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Off-Axis Cavity Ring Down Spectroscopy Based on a Continuous-Wave Optical Parametric Oscillator will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1000946

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.