Reflective Lyot stop low-order wavefront control for future large space telescope coronagraphs

Abstract

Future large space telescope missions for directly imaging exoplanets with internal coronagraphs will require picometer level low-order wavefront control to reach the 1*10´10 starlight suppression required to detect terrestrial exoplanets. This paper aims to characterize the reflective Lyot stop Low-Order Wavefront Sensor (LLOWFS) for the application where a transmissive focal plane mask is used, such as the Vector Vortex Coronagraph (VVC). This paper first defines the control requirements for such a mission based on the low-order tolerance of the VVC. The LLOWFS performance is then derived through optical simulation and compared to the requirements. The performance is calculated as a function of the target star brightness and aperture size and the final closed-loop stability is simulated using varying models for telescope pointing jitter and wavefront drift. © 2023 SPIE.