Combined Wavefront Sensor with Internal Reference Source: experimental study

Abstract

A wavefront sensor (WFS) is the key element of ground and space-based adaptive telescopes that provides a high accuracy and reliability of the operation of an adaptive mirror control system. We developed a new WFS in the scope of the project of a 3.2 m adaptive astronomical telescope with a wide angular field of view [1]. It has two parts - channels: an autocollimation-point sensor and interferometric (or Hartmann) one. The WFS is to be installed at the autocollimation point of low efficiency hologram structure on the controllable surface of the adaptive mirror [2]. Such a WFS combines two useful features: a high accuracy of interferometers and a wide angular range of operation in comparison with ordinary interferometers. Therefore, it provides the necessary information for initial alignment of the mirror and allows to diminish requirements to the rigidity of a telescope construction.