中国激光, 2020, 47 (9): 0904008, 网络出版: 2020-09-16
基于小波变换的平板波前死条纹噪声滤除方法 下载: 779次
Filtering Method of Fixed Pattern Noise in Window Wavefront Based on Wavelet Transform
测量与计量 干涉检测 寄生干涉 死条纹 小波变换 光学平板 measurement and metrology interferometry parasitic interference fixed pattern wavelet transform optical window
摘要
高功率激光器的建造需要大量的高精度光学平板,其波前检测一般采用相移干涉技术。由于测试光在光学平板内的多次反射,存在由寄生干涉导致的死条纹现象。死条纹会在波前检测结果中引入周期性相位噪声,极大降低了波前检测结果的置信度。针对该问题,提出了一种基于小波变换的降噪方法,可根据死条纹噪声特征对波前检测结果进行降噪,不需要额外硬件或调整测试状态。实验结果表明,该方法可以有效滤除死条纹引入的相位噪声,且能很好地保留加工特征。
Abstract
The construction of high-power laser needs a lot of high precision optical windows, and the wavefront detection generally uses phase-shifting interference technology. Due to the multiple reflections of the test light beam in the optical window, there is a fixed pattern phenomenon caused by parasitic interference. Fixed pattern will introduce periodic phase noise into wavefront detection results, which greatly reduces the confidence level of wavefront detection results. To address this problem, this paper presents a method based on wavelet transform to directly filter out the noise from the wavefront detection results according to the characteristics of fixed pattern noise without additional hardware or adjusting the test state. Experimental results demonstrate that this method can effectively filter out the phase noise caused by fixed pattern, and preserve the processing features well.
徐凯源, 李大海, 刘昂, 柴立群, 何宇航, 陈宁. 基于小波变换的平板波前死条纹噪声滤除方法[J]. 中国激光, 2020, 47(9): 0904008. Xu Kaiyuan, Li Dahai, Liu Ang, Chai Liqun, He Yuhang, Chen Ning. Filtering Method of Fixed Pattern Noise in Window Wavefront Based on Wavelet Transform[J]. Chinese Journal of Lasers, 2020, 47(9): 0904008.