Kallapur Abhijit G, Boyson Toby K, Petersen Ian R, Harb Charles C
School of Engineering and Information Technology, University of New South Wales at the Australian Defence Force Academy, Canberra, ACT, Australia.
Opt Express. 2011 Mar 28;19(7):6377-86. doi: 10.1364/OE.19.006377.
This paper discusses the application of a discrete-time extended Kalman filter (EKF) to the problem of estimating the decay time constant for a Fabry-Perot optical cavity for cavity ring-down spectroscopy (CRDS). The data for the estimation process is obtained from a CRDS experimental setup in terms of the light intensity at the output of the cavity. The cavity is held in lock with the input laser frequency by controlling the distance between the mirrors within the cavity by means of a proportional-integral (PI) controller. The cavity is purged with nitrogen and placed under vacuum before chopping the incident light at 25 KHz and recording the light intensity at its output. In spite of beginning the EKF estimation process with uncertainties in the initial value for the decay time constant, its estimates converge well within a small neighborhood of the expected value for the decay time constant of the cavity within a few ring-down cycles. Also, the EKF estimation results for the decay time constant are compared to those obtained using the Levenberg-Marquardt estimation scheme.
本文讨论了离散时间扩展卡尔曼滤波器（EKF）在估计用于光腔衰荡光谱（CRDS）的法布里-珀罗光学腔的衰减时间常数问题中的应用。估计过程的数据是从CRDS实验装置中获取的，以腔输出处的光强形式呈现。通过比例积分（PI）控制器控制腔内镜子之间的距离，使腔与输入激光频率保持锁定。在以25kHz斩波入射光并记录其输出光强之前，先用氮气吹扫腔并将其置于真空中。尽管在衰减时间常数的初始值存在不确定性的情况下开始EKF估计过程，但在几个衰荡周期内，其估计值在腔衰减时间常数预期值的小邻域内收敛良好。此外，还将衰减时间常数的EKF估计结果与使用列文伯格-马夸尔特估计方案获得的结果进行了比较。
