Predictive Wavefront Control: Modern AO systems typically suffer from millisecond time lags between measuring and correcting for atmospheric turbulence; predictive wavefront control compensates for these time lags using previous wavefront measurements. My group has implemented predictive control as part of the pyramid wavefront sensor real time control system at Keck II. We demonstrated a 2X RMS wavefront error improvement due to predictive control during daytime testing in Jensen-Clem et al. 2019, and an on-sky contrast improvement of 2-3X in van Kooten et al. 2021:
van Kooten et al. 2021
The Santa Cruz Extreme AO Lab: SEAL is a new visible-wavelength testbed designed to advance the state of the art in wavefront control for high contrast imaging on large, segmented, ground-based telescopes. SEAL simulates atmospheric turbulence using a custom Meadowlark spatial light modulator that delivers phase offsets of up to 6pi at 635nm. A 37-segment IrisAO deformable mirror (DM) simulates the W. M. Keck Observatory segmented primary mirror. The adaptive optics system consists of a woofer/tweeter deformable mirror system (a 97-actuator ALPAO DM and 1024-actuator Boston Micromachines MEMs DM, respectively), and four wavefront sensor arms: 1) a high-speed Shack-Hartmann WFS, 2) a reflective pyramid WFS, designed as a prototype for the ShaneAO system at Lick Observatory, 3) a vector-Zernike WFS, and 4) a Fast Atmospheric Self Coherent Camera Technique (FAST) demonstration arm, consisting of a custom focal plane mask and high-speed sCMOS detector. SEAL’s real time control system is based on the Compute and Control for Adaptive optics (CACAO) package, and is designed to support the efficient transfer of software between SEAL and the Keck II AO system. Learn more about SEAL in our recent SPIE Proceedings article: Jensen-Clem et al. 2021!
Jensen-Clem et al. 2021
The Planetary Systems Imager (PSI) at the Thirty Meter Telescope: PSI is a proposed instrument for the Thirty Meter Telescope that provides an extreme adaptive optics correction to a multi-wavelength instrument suite optimized for high contrast science. I am working to simulate the contrast delivered by PSI in the near-infrared. See Jensen-Clem et al. 2021 for more details.
Fitzgerald et al. 2018