Frequency Agile Lidar Receiver for Chem-Bio Sensing
PHYSICAL SCIENCES INC ANDOVER MA
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Physical Sciences Inc. PSI, in conjunction with its subcontractor, VTech Engineering Corp., developed an ultra low noise receiver module RM for direct detection LWIR LIDAR systems. The receiver module is compatible with emerging LWIR source technologies, e.g., optical parametric amplifier-based sources, as well as existing frequency-agile CO2 laser technology. In this paper we present RM performance attributes based on characterization experiments performed in the laboratory, as well as part of the system integration in the ECBCs Frequency Agile LIDAR FAL unit. The RM has been demonstrated to be compatible with a 200 Hz shot-to-shot line tuned CO2 laser in terms of both tuning speed and wavelength accuracy. The system achieves tuning times of less than 5 msec for wavenumber jumps 10 cm-1 and transmission measurement errors of 0.5 due to etalon absolute positioning uncertainty. The system has been demonstrated to achieve a total Noise Equivalent Power NEP of 1.7 nW for an electronic bandwidth of 5 MHz when observing a background of Tbkgd 400K. This represents 40 improvement over an equivalent detectorpreamplifier configuration without PSIs tunable etalon technology.
- Optical Detection and Detectors
- Radiofrequency Wave Propagation