Beam geometry, alignment, and wavefront aberration effects on interferometric differential wavefront sensing
Beam geometry, alignment, and wavefront aberration effects on interferometric differential wavefront sensing
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DOI：
10.1088/0957-0233/26/12/125203
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发表时间：
2015-10
影响因子：
2.4
通讯作者：
Xiangzhi Yu;S. Gillmer;J. Ellis
中科院分区：
文献类型：
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作者：
Xiangzhi Yu;S. Gillmer;J. Ellis
外差干涉测量是一种广泛接受的方法，在许多计量应用中具有高分辨率。作为一种功能增强，差分波前传感（DWS）能够使用位移干涉测量系统和入射在平面镜目标上的单个光束来同时测量位移、俯仰和偏航。使用对称相邻象限光电二极管对之间的加权相位平均来测量角度变化。本文提出了一种基于基模高斯光束的微分相位信号标度的解析模型。几个数值模型，讨论了物理光束参数，探测器的尺寸，系统的对准误差，光束波前像差的DWS技术的影响。我们的建模结果预测旋转比例因子和可用的线性范围。此外，实验结果表明，解析预测的标度因子与经验校准吻合良好。我们的三自由度干涉仪可以同时获得0.4 nm的位移分辨率和0.2 μrad的俯仰和偏航分辨率。
Heterodyne interferometry is a widely accepted methodology with high resolution in many metrology applications. As a functionality enhancement, differential wavefront sensing (DWS) enables simultaneous measurement of displacement, pitch, and yaw using a displacement interferometry system and a single beam incident on a plane mirror target. The angular change is measured using a weighted phase average between symmetrically adjacent quadrant photodiode pairs. In this paper, we present an analytical model to predict the scaling of differential phase signals based on fundamental Gaussian beams. Several numerical models are presented to discuss the effects of physical beam parameters, detector size, system alignment errors, and beam wavefront aberrations on the DWS technique. The results of our modeling predict rotational scaling factors and a usable linear range. Furthermore, experimental results show the analytically predicted scaling factor is in good agreement with empirical calibration. Our three degree-of-freedom interferometer can achieve a resolution of 0.4 nm in displacement and 0.2 μrad in pitch and yaw simultaneously.