High-Contrast Imaging using Adaptive Optics for Extrasolar Planet Detection

摘要: Direct imaging of extrasolar planets is an important, but challenging, next step in planetary science. Most identified to date have been detected indirectly--not by emitted or reflected light through the effect planet on parent star. For example, radial velocity techniques measure doppler shift spectrum star produced presence a planet. Indirect only probe about 15% orbital parameter space our solar system. methods would new space, and can be analyzed spectroscopically, providing information planets. High contrast adaptive optics systems, also known as Extreme Adaptive Optics (ExAO), will require contrasts between 10{sup -6} -7} at angles 4-24 {lambda}/D 8-m class telescope image young Jupiter-like still warm with heat formation. Contrast defined intensity ratio dark wings image, where might be, bright core Such instruments technically requiring high order > 2000 actuators improved diffraction suppression. ultimately limited residual static wavefront errors, so more » imager control accuracy better than 1 nm rms within low- mid-spatial frequency range. Laboratory demonstrations are critical instrument development. The ExAO testbed for was designed low error precision optical metrology, which used explore limits develop technology needed imager. A state-of-the-art, 1024-actuator micro-electrical-mechanical-systems (MEMS) deformable mirror installed characterized provide active test this novel technology. I present 6.5 x -8} measurements prolate shaped pupil flat demonstrating that operate necessary regime. Wavefront simulations indicate error, not diffraction. demonstrate feasibility MEMS meeting stringent requirements closed-loop results 0.54 controllable spatial frequencies. Individual contributors final quality characterized. 2 made device identify amplitude errors limiting source. Closed-loop performance simulated far-field using Kolmogorov phase plate introduce atmosphere-like presented. « less