Among the results obtained in the context of Mathilde Beaulieu's PhD thesis, her work has made possible to set the distance separating the 2 kilo-C deformable mirrors of the SPEED bench taking into account the Fresnel/Talbot effects, and the high contrast at small angular separation objective of the project. The first mirror DM1 is localized at 0.25 m upstream of the pupil plane, and the second mirror DM2 is at 1.5 m downstream of the pupil plane. The 2 mirrors are out-of-the pupil plane and separated by ~ 1.7 m. The figure (extracted from Beaulieu et al., MNRAS 2017) presents histograms (over 128 realizations) of 5 sigma contrast obtained in simulation by varying the positioning of the DM1 (z1) and DM2 (z2) for an error budget of 20 nm rms (black) and 40 nm rms (red). The simulation takes the hypothesis of a perfect coronograph, a monolithic pupil, and generates dark holes with the EFC.
