For the efficient operation of a cavity ringdown spectroscopy (CRDS) system utilized with a continuouswave (cw) laser, we numerically analyze the coupling efficiency of a cw laser to a ringdown cavity in terms of changes in the scanning rate, the laser linewidth, and the mirror reflectivity. We also demonstrate a new simple design for a CRDS system that can produce a CRDS signal with only a piezoelectric transducer (PZT), without the acousto-optic modulator that is usually adopted to switch off the cw laser beam that enters the cavity. Furthermore, we investigate the feasibility of the cw CRDS technique with a fast-scanning PZT by recording a CRDS spectrum of acetylene overtones. The detection sensitivity that corresponds to the noise-equivalent absorption is found to be -3 × 10−-9/cm.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering