Ultrafast InGaAs PIN Detector for Eyesafe LIDAR

F. J. Effenberger & Abhay M. Joshi
Discovery Semiconductors, Inc.
119 Silvia Street
Ewing, New Jersey, 08628 USA

ABSTRACT

Eyesafe LIDAR systems require detectors that operate in the 1.55 micron band with high bandwidth and large area. This paper describes the three design methods used in developing such detectors. First, a thick dual-depletion width PIN structure is optimized for low capacitance and transit time. This enables the detector itself to have the best intrinsic speed. Second, an extra-low input impedance preamplifier is designed. This preamplifier improves the performance of the already fast pin by lowering the electrical time-constants of the readout. Third, a novel partitioned detector layout is developed. This technique allows the connection of a large number of small, highspeed segments in parallel to form a single large detector. When used in combination, these design methods can produce a new class of detectors with diameters greater than 1 mm and bandwidths greater than 4 GHz.

Keywords: InGaAs, LIDAR, large area detector, ultrafast, eyesafe.

* Presented & Published at SPIE's AeroSense Conference 13-17 April 1998