Engineering topics

Green, S. I.

Publications and source records attributed to Green, S. I..

4 records

NASA NTRS1978

High-speed communication detector characterization by bit error rate measurements

Performance data taken on several candidate high data rate laser communications photodetectors is presented. Measurements of bit error rate versus signal level were made in both a 1064 nm system at 400 Mbps and a 532 nm system at 500 Mbps. RCA silicon avalanche photodiodes are superior at 1064 nm, but the Rockwell hybrid 3-5 avalanche photodiode preamplifiers offer potentially superior performance. Varian dynamic crossed field photomultipliers are superior at 532 nm, however, the RCA silicon avalanche photodiode is a close contender.

Green, S. I.↗

NASA NTRS1977

Wideband 1.064 micrometer detector evaluation

Several types of communications detectors for use in a 400 Mbps 1.064 micrometer laser communication system were evaluated and characterized. The communication system Bit Error Rate (BER) performance was measured, and test results for the best detector of each type are summarized. The complete BER curves are presented. The 400 Mbps 1.064 micrometer communication system receiver test bed is described. The best performance levels which can be achieved by focusing the signal to diffraction limited spots on the photosensitive area are cited.

Green, S. I.↗

NASA NTRS1975

Wideband 1.064 micrometer detector evaluation

The performance of several candidate detectors for use as communications detectors in a 400 Mbps 1.064 micrometers laser communication system was evaluated. The results of communication system Bit Error Rate (BER) testing for the best detector of each type are summarized. Complete testing data of each type detector is presented. The 400 Mbps 1.064 micrometers communication system receiver test bed is described. The best communication system results for each detector type are included. Performance comparisons are made at 0.000001 BER, the specification level chosen for satellite laser communication links. The data is presented in two groups. The first indicates the best performance levels that can be expected on normal space laser communication system operation. The second cites the best performance levels which can be achieved by focusing the signal to diffraction limited spots on the photosensitive area.

Green, S. I.↗

NASA NTRS1973

Gated high speed optical detector

The design, fabrication, and test of two gated, high speed optical detectors for use in high speed digital laser communication links are discussed. The optical detectors used a dynamic crossed field photomultiplier and electronics including dc bias and RF drive circuits, automatic remote synchronization circuits, automatic gain control circuits, and threshold detection circuits. The equipment is used to detect binary encoded signals from a mode locked neodynium laser.

Green, S. I.↗