Laboratory test of a polarimetry imaging subtraction system for the high-contrast imaging

摘要

We propose a polarimetry imaging subtraction test system that can be used for the direct imaging of the reflected lightfrom exoplanets. Such a system will be able to remove the speckle noise scattered by the wave-front error and thus canenhance the high-contrast imaging. In this system, we use a Wollaston Prism (WP) to divide the incoming light into twosimultaneous images with perpendicular linear polarizations. One of the images is used as the reference image. Thenboth the phase and geometric distortion corrections have been performed on the other image. The corrected image issubtracted with the reference image to remove the speckles. The whole procedure is based on an optimization algorithmand the target function is to minimize the residual speckles after subtraction. For demonstration purpose, here we onlyuse a circular pupil in the test without integrating of our apodized-pupil coronagraph. It is shown that best result can begained by inducing both phase and distortion corrections. Finally, it has reached an extra contrast gain of 50-timesimprovement in average, which is promising to be used for the direct imaging of exoplanets.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.