PROCEEDINGS ARTICLE | February 23, 2006
Proc. SPIE. 6119, Semiconductor Photodetectors III
KEYWORDS: Photodetectors, Photon counting, Avalanche photodetectors, Optical amplifiers, Sensors, Interference (communication), Amplifiers, Analog electronics, Signal detection, Solid state photomultipliers
We have designed and developed a new family of photodetectors with Internal Discrete Amplification (IDA) mechanism
They operate as solid state photomultiplier devices at room temperature and may be used in numerous applications
where high bandwidth of the detector is necessary in combination with maximum sensitivity and low excess noise. The
photodetectors can operate in linear detection mode with gain-bandwidth product up to 5 times 1014 as well as in photon
counting mode with count rates up to 108 counts/sec. The key performance characteristics exceed those of
Photomultiplier Tube (PMT) and Avalanche Photodiode (APD) devices. The detectors have gain > 105, excess noise
factor as low as 1.03, photoresponse rise/fall time < 300 ps, and timing resolution (jitter) < 200 ps. The combination of
low excess noise at high gain and wide bandwidth, as well as scalability to large active areas, presents the main
advantages of this technology over conventional photodetector solutions. Ultra low excess noise is one of the main
features of the internal Discrete Amplification Detector (DAD), and in this paper its nature has been investigated more
comprehensively. We investigated the behavior of the noise-factor and afterpulsing, and conclude that both have the
same physical nature. Optical cross-talk between channels is shown to be responsible for the afterpulsing phenomenon,
and, in turn, is the main source of excess noise. Thus, the noise characteristics of an DAD device and its timing
resolution may be significantly improved as they are limited not by the discrete amplifier channel properties itself, but by
the cross-talk, which strongly depends on the device design.
