Wavefront Sensing by a Common-Path Interferometer for Wavefront Correction in Phase and Amplitude by a Liquid Crystal Spatial Light Modulator Aiming the Exoplanet Direct Imaging

Abstract

We implemented the common-path achromatic interfero-coronagraph both for the wavefront sensing and the on-axis image component suppression, aiming for the stellar coronagraphy. A common-path achromatic interfero-coronagraph has its optical scheme based on a nulling rotational-shear interferometer. The angle of rotational shear can be chosen at a small angular extent of about 10 deg. Such a small angular shear maintains the coronagraphic contrast degradation known as the stellar leakage effect, caused by a finite stellar size. We study the phase and amplitude wavefront control by a liquid crystal spatial light modulator of reflection type which is used as the pixilated active adaptive optics unit. Therefore, adaptive optics perform a wavefront-correcting input toward a stellar interfero-coronagraph aiming at the direct exoplanet imaging. Presented here are both the numeric evaluations and the lab experiment stand to prove the declared functionality output.

Keywords

• exoplanet direct imaging
• adaptive optics
• wavefront sensing and correction
• phase-shifting interferometry
• interfero-coronagraph
• common-path