Data point selection for weighted least square fitting of cavity decay time constant**Project supported by the Preeminent Youth Fund of Sichuan Province, China (Grant No. 2012JQ0012), the National Natural Science Foundation of China (Grant Nos. 11173008, 10974202, and 60978049), and the National Key Scientific and Research Equipment Development Project of China (Grant No. ZDYZ2013-2).

Abstract

For the accurate extraction of cavity decay time, a selection of data points is supplemented to the weighted least square method. We derive the expected precision, accuracy and computation cost of this improved method, and examine these performances by simulation. By comparing this method with the nonlinear least square fitting (NLSF) method and the linear regression of the sum (LRS) method in derivations and simulations, we find that this method can achieve the same or even better precision, comparable accuracy, and lower computation cost. We test this method by experimental decay signals. The results are in agreement with the ones obtained from the nonlinear least square fitting method.