Pulsed, single-mode cavity ringdown spectroscopy.
Pulsed, single-mode cavity ringdown spectroscopy.
复制标题
DOI：
10.1364/ao.38.003951
复制
发表时间：
1999-06
期刊：
影响因子：
1.9
通讯作者：
R. V. van Zee;J. Hodges;J. Looney
中科院分区：
文献类型：
--
作者：
R. V. van Zee;J. Hodges;J. Looney
我们讨论了使用单模腔衰荡光谱与脉冲激光定量气体密度和线强度测量。单模腔衰荡光谱方法给出了没有模式拍频的单指数衰减信号，这使得测量的不确定性接近散粒噪声极限。该技术证明了一个10厘米长的衰荡腔和脉冲，稳频光参量振荡器作为光源。噪声等效吸收系数为5 × 10 ~（-10）cm ~（-1）Hz ~（-1/2），从拟合单个衰荡曲线中提取的衰荡时间的相对标准偏差（sigma（tau）/tau）与数百个独立测量的集合相同。线强度的重复测量显示具有<0.3%的标准偏差。正态分布的噪声对测量的量使用腔衰荡光谱的影响进行了讨论，在衰荡时间的相对标准偏差的公式给出了在拍摄和技术噪声的限制，并在这些限制的噪声等效吸收系数进行了比较脉冲和连续波光源。
We discuss the use of single-mode cavity ringdown spectroscopy with pulsed lasers for quantitative gas density and line strength measurements. The single-mode approach to cavity ringdown spectroscopy gives single exponential decay signals without mode beating, which allows measurements with uncertainties near the shot-noise limit. The technique is demonstrated with a 10-cm-long ringdown cavity and a pulsed, frequency-stabilized optical parametric oscillator as the light source. A noise-equivalent absorption coefficient of 5 x 10(-10) cm(-1) Hz(-1/2) is demonstrated, and the relative standard deviation in the ringdown time (sigma(tau)/tau) extracted from a fit to an individual ringdown curve is found to be the same as that for an ensemble of hundreds of independent measurements. Repeated measurement of a line strength is shown to have a standard deviation <0.3%. The effects of normally distributed noise on quantities measured using cavity ringdown spectroscopy are discussed, formulas for the relative standard deviation in the ringdown time are given in the shot- and technical-noise limits, and the noise-equivalent absorption coefficient in these limits are compared for pulsed and continuous-wave light sources.