探测器孔径大小对衰荡腔测量精度的影响

Influence of detector’s aperture on metrical precision of ring-down cavity

摘要: 为了研究光腔衰荡光谱法的反射率测量精度,分析了腔长失调对衰荡腔模式影响。在此基础上,根据高斯光束空间传输表达式,推导了在一定腔长失调条件下,探测器孔径与衰荡脉冲信号的关系式。并利用数值模拟,分析了衰荡腔测量精度与探测器孔径大小的关系。结果表明,探测器孔径越大,测量的相对误差越小。

Abstract: In order to study the metrical precision of reflectivity via cavity ring-down spectroscopy,first of all,it is investigated that influence of length misadjustment of ring-down cavity on its mode coupling.Then,based on propagation of Gaussian beam,it is deduced that relation between detector's aperture and output power of ring-down cavity of length misadjustment,and it is also numerically simulated that influence of detector's aperture on metrical precision.Results show that the bigger the detector's aperture is,the lower the metrical relative error is.