title: Cavity ringdown spectroscopy with a continuous-wave laser: calculation of coupling efficiency and a new spectrometer design.
abstract: For the efficient operation of a cavity ringdown spectroscopy (CRDS) system utilized with a continuous-wave (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 approximately 3 x 10(-9)/cm.
authors.affiliation: Optical High Temperature Measurement Group, Korea Research Institute of Standards and Science, PO Box 102, Yusong, Taejon 305-600, Korea.
authors.forename: J W
authors.initials: JW
authors.lastname: Hahn
authors.forename: Y S
authors.initials: YS
authors.lastname: Yoo
authors.forename: J Y
authors.initials: JY
authors.lastname: Lee
authors.forename: J W
authors.initials: JW
authors.lastname: Kim
authors.forename: H W
authors.initials: HW
authors.lastname: Lee