UA wavefront control lab: Design overview and implementation of new wavefront sensing techniques

We present an overview of the design of a new testbed for studying coronagraphic imaging and wavefront control using a variety of pupil and coronagraph architectures. The testbed is designed to explore optimal use of starlight (including starlight rejected by the coronagraph) for wavefront control, system self-calibration, and point spread function (PSF) calibration. It is also compatible with coronagraph designs for centrally obscured and segmented apertures, and includes shaped or apodized pupils, a range of focal plane masks and Lyot stops of multiple sizes, and an optional PIAA apodizing stage. Starlight is reflected and imaged from the focal plane mask and Lyot stop for low-order wavefront sensing. Both a segmented and a continuous sheet MEMS DM are included to simulate segmented telescope pupils, apply known test phase patterns, and implement a controllable phase apodization coronagraph. The testbed is adaptable and is currently being used to investigate three different techniques: (1) the differential optical transfer function (dOTF), (2) low-order wavefront sensing (LOWFS) with a hybrid-Lyot coronagraph, and (3) linear dark field control (LDFC).