Scott Severson

TL;DR: The Lick Observatory is pursuing new technologies for adaptive optics that will enable feasible low-cost laser guidestar systems for visible wavelength astronomy as discussed by the authors, and the Villages system, commissioned at the 40 inch Nickel Telescope this past fall, serves as an on-sky testbed for new deformable mirror technology (high-actuator count MEMS devices), open-loop wavefront sensing and control, and laser uplink correction.

TL;DR: In this paper, the performance of Boston Micromachines' 1024-actuator continuous-facesheet MEMS deformable mirrors under tests for actuator stability, position repeatability, and practical operating stroke was evaluated.

TL;DR: In this article, a semi-empirical technique is described that improves the determination of the AO off-axis point spread function (PSF) by using calibration images of dense star fields to determine the change in PSF with field position.

TL;DR: In this article, the authors used a simple optical design to minimize wavefront error and maximize the experimentally achievable contrast, using a phase shifting diffraction interferometer (PSDI) as the wavefront sensor.

TL;DR: The Lick Observatory laser guide star adaptive optics system has undergone continual improvement and testing as it was being integrated as a facility science instrument on the Shane 3 meter telescope as discussed by the authors, and both NGS and LGS modes are now used in science observing programs.