Research Interests

As an astrophysicist, I work on developing and expanding a new technique called "adaptive optics." The spatial resolution of images taken by ground-based telescopes is strongly limited by turbulence in the earth's atmosphere. Adaptive optics (AO) measures the atmospheric turbulence above a telescope hundreds of times a second, and uses this information to reshape a special "deformable mirror" that removes the optical aberrations caused by the turbulence. The result is a factor of 10 to 20 improvement in spatial resolution on today's largest 8-10m ground-based telescopes, which with AO at infrared wavelengths can perform at their diffraction limit. To measure the turbulence for a larger fraction of places in the sky, I led the development of the first "laser guide stars" at Lick and Keck Observatories based on excitation of the D2 line of atomic sodium at an altitude of about 100 km. I am currently the Project Scientist for Keck Observatory's Next Generation AO system, which will yield image improvement at shorter wavelengths and over a larger area. I am using today's AO systems to study the mergers of nearby colliding galaxies, and to measure the masses of the super-massive black holes that reside in their cores.

Membership Type


Election Year


Primary Section

Section 12: Astronomy

Secondary Section

Section 13: Physics