Photon counting EMCCD developments for the WFIRST coronagraph (Conference Presentation)

A photon counting camera based on the Teledyne-e2v CCD201-20 electron multiplying CCD (EMCCD) is being developed for the NASA WFIRST coronagraph, an exoplanet imaging technology development of the Jet Propulsion Laboratory (Pasadena, CA) that is scheduled to launch in 2026. The coronagraph is designed to directly image planets around nearby stars, and to characterize their spectra. The planets are exceedingly faint, providing signals similar to the detector dark current, and require the use of photon counting detectors. Red sensitivity (600-980nm) is preferred to capture spectral features of interest. EMCCDs are baselined both as science and wavefront sensors in the coronagraph in order to simplify the system architecture. We are engaged in a test program to characterize the performance of the EMCCD in the required modes, as well as in a technology development program with Teledyne-e2v to ruggedize the sensors for use in space. In this paper we will summarize our progress, program status, and plans for flight development.