Adaptive Optics Systems for the Thirty Mirror Telescope

TMT Observatory Corporation

^a e-mail: brente@caltech.edu

Abstract

At first light, the overall AO system architecture for the Thirty Meter Telescope will consist of the Narrow Field Infra-Red AO System (NFIRAOS) and the associated Laser Guide Star Facility (LGSF). NFIRAOS is an order 60x60, dual conjugate, laser guide star AO system designed to obtain diffraction-limited performance in the near IR with high sky coverage. It will provide a delivered wavefront error of 190-200 nm RMS over a central 15-30 arc second field-of-view, and a lesser degree of atmospheric turbulence compensation over a larger 2 arc minute field for multi-object spectroscopy and low order (tip/tilt/focus) natural guide star wavefront sensing in the near IR. The LGSF generates 6 sodium laser guidestars for use with NFIRAOS, using 6 25-watt lasers located in the telescope azimuth structure and a laser launch telescope behind the TMT secondary mirror. In this paper, we review the work to date on requirements derivation, design development, performance analysis, component prototyping, and lab/field tests for these AO systems. The possible options for future MOAO, ExAO, GLAO, and MIRAO systems for TMT are also briefly described.