New tubeless nanosecond streak camera based on optical deflection and direct CCD imaging

Abstract

A new optically deflected streaking camera with performance of nanosecond-range resolution, superior imaging quality, high signal detectability, and large format recording has been conceived and developed. Its construction is composed of an optomechanical deflector that deflects the line-shape image of spatial-distributed time-varying signals across the sensing surface of a cooled scientific two-dimensional CCD array with slow readout driving electronics, a lens assembly, and a desk-top computer for prompt digital data acquisition and processing. Its development utilizes the synergism of modern technologies in sensor, optical deflector, optics and microcomputer. With laser light as signal carrier, the deflecting optics produces near diffraction-limited streak images resolving to a single pixel size of &lt;EQ 25 micrometers <SUP>2</SUP>. A 1kx1k-pixel array can thus provide a vast record of 1,000 digital data points along each spatial or temporal axis. High signal detectability is expected from the combined advantage of sharp focusing, 75% QE 514 nm of a thinned backside-illuminated CCD, absence of any undesirable signal conversion involving diffusing emission or inefficient coupling, and low noise of CCD readout electronics. Since only one photon-to-electron conversion exists in the entire signal recording path, the camera responses linearly to the incident light over a wide dynamic range in excess of 10<SUP>4</SUP>:1.