Laboratory test results for adaptive optics using image-based wavefront sensing for remote sensing

Abstract

Large aperture optical system is required for high resolution and high signal to nose ratio remote sensing observations. In this case, adaptive optics is used to compensate the wavefront aberration generated by the misalignment or the thermal deformation of the optical elements. We use a liquid crystal on silicon spatial light modulator (LCOS-SLM) for the optical wavefront control, and image-based wavefront sensing which realize simple hardware architecture. For image-based sensing, a priori information is required in addition to the acquired images. We use phase diversity (PD) wavefront sensing method which applies a priori information called PD to the optics. By using PDs and acquired images, we can estimate arbitrary wavefront aberration. In this case, the sensitivity of the acquired image to the aberration mode depends on the applied PD. We use LCOS-SLM to apply the optimal set of PDs. We constructed adaptive optics system testbed using LCOS-SLM and USB camera. In this system, we used a Shack-Hartmann wavefront sensor (SHWS) to compare the estimated wavefront aberration with the actual wavefront measured by the SHWS. The laboratory test results show that the proposed system improves the optical performance of the remote sensing sensors.