Deformable Mirror Controller for Open-Loop Adaptive Optics

A Deformable Mirror Controller (DMC) has been devised to overcome the open-loop nature of Multi Object Adaptive Optics (MOAO), in particular for AO systems with update rates of I Ins or less. The system is based on a figure sensor, which uses a monochromatic illumination source and a Shack-Hartmann (SH) wavefront sensor (WFS) to obtain a fine sampling of DM's 3D Surface. The sensor's beam is optically separated from the science path in order to not interfere with science observations. The DMC incorporates a real-time controller in charge of driving the DM. This controller runs in a dedicated Field-Programmable-Gate-Array (FPGA) based processor to keep LIP with stringent speed requirements. The DMC is being tested in the laboratory and is part of CANARY, an MOAO on-sky demonstrator to be installed at the William Hershel Telescope.