Enabling new high contrast imaging science on Subaru Telescope with Electron Multiplying CCDs

We are testing a photon-counting electron multiplying CCD (EMCCD) for use in the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system. We intend to use EMCCD technology on the SCExAO system for (1) high performance wavefront sensing for Extreme-AO and (2) diffraction limited visible light science imaging. For both applications, the ability to operate in photon-counting mode is highly advantageous, and we are currently conducting laboratory tests to quantify the EMCCD performance for these applications. The EMCCD technology is also attractive as a higher sensitivity alternative to the Avalanche Photodiodes (APDs) currently used by Subaru 188-actuator adaptive optics system.