NASA 1996 SBIR Phase I

PROJECT TITLE : 20,000 frame per second delta-doped electron-bombarded CCD Wavefront Sensor

TECHNICAL ABSTRACT (LIMIT 200 WORDS)

PixelVision, Inc. as team leader proposes to design, manufacture, test, and optimize a high speed, low noise, electron bombarded CCD (EBCCD) adaptive optics wavefront that will result in a new class of high frame rate, low light level imagers that can be optimized to operate either: 1) the ultra-violet (0.2 to 0.5 mm), 2) the visible (0.4 to 0.95 mm) spectral region; or 2) the NIR (0.95 to 1.8 mm wavelength) spectral regions. The innovation uses a high frame, low noise back-illuminated CCD that when integrated with a photocathode and operated in the electron bombarded mode allows high frame rate photon counting. By providing nearly noiseless gain, without a microchannel plate, the wavefront sensing EBCCD does not suffer from the drawbacks of other image tube and intensified imaging approaches. An ideal sensor for wavefront and adaptive optics low light level imaging applications does not presently exist. Cooling requirements, large pixel size, poor signal to noise, phosphor persistence, poor resolution, blooming and difficult manufacture all plague the currently competing technologies. A high speed imager with high signal to noise performance is required. PixelVision, Inc. a leader in high performance CCD design and manufacture proposes development of a hybrid imager that will have the following characteristics: 1) Greater than 35 percent quantum efficiency at 0.7 mm in a GaAs photocathode EBCCD, 2) Greater than 15 percent quantum efficiency between 1.2 and 1.7 mm in a transfer electron InP:InGaAs photocathode , 3) greater than 15 percent quantum at 0.25 mm efficiency in a bi-alkali photocathode coupled in a vacuum tube with a thinned and back-illuminated CCD; 3) Nearly ideal noiseless EBS gain that will allow photon counting noise performance at high frame rates; and 4) 128 x 128 element resolution, and 5) Greater than 20,000 frame per second operation. Molecular beam epitaxy (MBE) delta-doping, a process developed at JPL, will be used to provide a stable back surface treatment that is capable of providing a back-illuminated CCD with high EBS gain.

The development of the proposed sensor will expand markets requiring affordable high frame rate sensors in the UV, visible and NIR spectral regions. NIR lasers applications and the emerging UV lasers require high resolution, high frame rate image sensors. Opportunities for the Visible/NIR sensor include: motion analysis, eye-safe LIDAR, adaptive optics, underwater imaging, range gated imaging in adverse weather conditions, surveillance, space based wavefront imaging, neural imaging, and industrial inspection and robotics.

Typed Name James R. Janesick
Title Chief Scientific Officer
FIRM NAME PixelVision, Inc
MAIL ADDRESS 15250 NW Greenbrier Parkway
CITY/STATE/ZIP Beaverton, OR 97006

Typed Name George M. Williams
Title General Manager
FIRM NAME PixelVision, Inc
MAIL ADDRESS 15250 NW Greenbrier Parkway
CITY/STATE/ZIP Beaverton, OR 97006