Single-photon-sensitive EBCCD with additional multiplication

摘要

A highly sensitive image sensor for single photon imaging has been developed. The sensor (referred as an intensified EBCCD here) contains a photocathode, a microchannel plate (MCP) and an electron-sensitive CCD in a vacuum tube. In response to incident photons, electrons emitted from the photocathode are multiplied once by the MCP, further by the CCD and read out. Either an image intensifier containing MCPs or an EBCCD containing an electron-sensitive CCD has sensitivity for single photon by itself, however, many intense white spot-noise appear on output image and degrade the image quality seriously at such high-gain operation. In the case of intensified EBCCD reported here, since both the MCP and the electron-sensitive CCD are used for electron multiplication, high gain for single photon detection is available in total at low gains of both devices. This operation reduces the noise drastically, and improves the image quality. We have developed the intensified EBCCD with a GaAsP photocathode for high quantum efficiency, and evaluated the performance. Comparing with conventional cameras, such as an EM-CCD and an image intensifier, the intensified EBCCD shows superior detection capability at especially low-light level, that is single photon imaging.