Phase and Lyot-type coronagraphs for the High Order Testbench: prototyping and first laboratory results

Abstract

We report laboratory development of coronagraphic devices to be implemented on the High Order Testbench (HOT) to assess intensity reduction between them at a high Strehl ratio regime. The high order test bench implements extreme adaptive optics with realistic telescope conditions reproduced by star and turbulence generators. A 32×32 actuator micro deformable mirror, one pyramid wave front sensor, one Shack-Hartmann wave front sensor and the ESO SPARTA real-time computer. This will enable characterization and comparative study of different types of coronagraphs in realistic conditions. We have developed several prototypes of promising coronagraphs concepts: Four Quadrants Phase Mask¹ (FQPM), Lyot² coronagraphs and Apodized Pupil Lyot Coronagraph³ (APLC). We will describe the design of the IR coronagraphic path on HOT, prototyping processes used for each coronagraph and discuss quality control and first results obtained on a IR coronagraphic testbench (Strehl ratio ~ 94%). Finally, we will present our experiment plan and future coronagraph developments.