The Self-Coherent Camera: a new tool for planet detection

Abstract

The performance of high contrast imaging systems is very often limited by the presence of static speckles in the point-spread function of the central source. Several techniques have already been proposed to discriminate a faint companion from these residual speckles. These techniques used different criteria to separate a speckle from a companion: polarization, spectral information or coherence. Here, we propose a new imaging device, the Self-Coherent Camera (SCC), that is based on the lack of coherence between the stellar light and the planet that is searched for. This SCC is a simple instrument that allows us to reach the fundamental limitation of the photon noise by calibrating the speckles in the recorded images. After the description of the general problem of discriminating speckles from planets, we will explain the principle of the SCC. Then, we will analyze the different limitations of this technique as well as the performance that can be reached with current telescopes.