Boruah Bosanta R, Das Abhijit
Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
Appl Opt. 2011 Jul 10;50(20):3598-603. doi: 10.1364/AO.50.003598.
In this paper, we describe a zonal wavefront sensor in which the photodetector array can have a smaller number of rows. The test wavefront is incident on a two-dimensional array of diffraction gratings followed by a single focusing lens. The periodicity and the orientation of the grating rulings of each grating can be chosen such that the +1 order beam from the gratings forms an array of focal spots in the detector plane. We show that by using a square array of zones, it is possible to generate an array of +1 order focal spots having a smaller number of rows, thus reducing the height of the required detector array. The phase profile of the test wavefront can be estimated by measuring the displacements of the +1 order focal spots for the test wavefront relative to the +1 order focal spots for a plane reference wavefront. The narrower width of the photodetector array can offer several advantages, such as a faster frame rate of the wavefront sensor, a reduced amount of cross talk between the nearby detector zones, and a decrease in the maximum thermal noise. We also present experimental results of a proof-of-concept experimental arrangement using the proposed wavefront sensing scheme.
在本文中，我们描述了一种区域波前传感器，其中光电探测器阵列的行数可以更少。测试波前入射到二维衍射光栅阵列上，随后是一个单聚焦透镜。可以选择每个光栅的光栅刻线的周期和方向，使得来自光栅的 +1 级光束在探测器平面上形成一系列焦点。我们表明，通过使用方形区域阵列，可以生成行数更少的 +1 级焦点阵列，从而减小所需探测器阵列的高度。测试波前的相位分布可以通过测量测试波前的 +1 级焦点相对于平面参考波前的 +1 级焦点的位移来估计。光电探测器阵列较窄的宽度可以提供几个优点，例如波前传感器更快的帧率、附近探测器区域之间串扰量的减少以及最大热噪声的降低。我们还展示了使用所提出的波前传感方案的概念验证实验装置的实验结果。
