Project Title:

HIGH GAIN AVALANCHE PHOTODIODE ARRAYS FOR DEEP SPACE OPTICAL COMMUNICATIONS

Radiation Monitoring Devices, Inc.
44 Hunt Street
Watertown, MA 02172

93-1  14.02   1167    __      AMOUNT REQUESTED $70,000

HIGH GAIN AVALANCHE PHOTODIODE ARRAYS FOR DEEP SPACE OPTICAL COMMUNICATIONS

Abstract:

Space optical communications techniques are expected to be of great
value when communicating at planetary distances. As opposed to RF
systems, the high optical power concentration resulting from the
small beam divergence will allow smaller diameter telescopes, less
power and jam resistant communications. For deep space
communications, the low optical level available for detection at
the spacecraft presents challenging requirements in order to track
the optical source position with extremely high accuracy. Current
detection techniques do not have sufficient sensitivity at very low
light levels encountered in these applications.
This proposal presents a new high resolution, two-dimensional
silicon avalanche photodiode focal plane array, with an internal
gain higher than 108, fast time response and virtually without dead
space between the sensing pixels. Phase I is designed to
demonstrate the feasibility of producing high gain pixilated
avalanche photodiodes by using integrated circuit planar
technology. The detector is intended to be used as a
acquisition/tracking detector at very low optical levels with
applications in space optical communications.

Optical detectors are used in scientific, industrial, safety and
medical instrumentation. The market for them is hundreds of
millions of dollars. Phototubes represent the major portion of that
market. Because the avalanche photodiodes are compact, sensitive
and reliable it would gain a large share of the phototube market.

Avalanche photodiode, tracking, space optical communications