Simulation of the Lyot Coronograph

A coronagraph is a device which blocks light from the center of the telescope beam while permitting light from surrounding sources to pass through relatively undisturbed. Coronographs are used to image the faint surroundings of stars. First used for solar corona observations, coronographs have revealed a circumstellar disk around the star. This work consists at carrying out a complete simulation of diffraction since the pupil of opening until the focal plan of the coronographic pupil. The principle of the stellar coronograph of Lyot can be described by employing the formalism of the Fourier optics. In this work, we have developed a numerical simulation to evaluate the performances of the Lyot coronograph. Lastly, we will show some results of simulations of the coronograph associated with optics.