An ultraviolet nanosecond light pulse generator using a light emitting diode for test of photodetectors

Review of Scientific Instruments (Impact Factor: 1.58). 02/1997; 68(3):1365-1368. DOI: 10.1063/1.1147943

ABSTRACT An optical function pulse generator that emits (1) short pulse of 1 ns duration, (2) double pulse with variable time interval, and (3) square waveform pulse of variable width in nanosecond range is devised using an InGaN/AlGaN double heterostructure light emitting diode (LED). Although the LED emits a 450 nm (blue) light under conventional dc operation below 30 mA, 380 nm light due to the InGaN/AlGaN component appears when a current larger than 50 mA is applied. This phenomenon is used to realize a pulsed ultraviolet light source. Under large nanosecond current pulsing (peak current >1 A), an intense pulsed emission of 380 nm is obtained. Pulse waveform of the LED emission can be adjusted electrically by applying a shaped current to the LED. To evaluate the potential of the pulse generator as a test source of photodetectors, the response waveforms of photomultiplier tubes were measured. © 1997 American Institute of Physics.

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