Bayarto Lubsandorzhiev ((Institute for Nuclear Research of RAS))
Powerful nanosecond light sources based on LEDs have been developed for use in calibration systems of deep underwater neutrino experiments. The designs of such sources are described. The light sources use either matrixes of ultra bright blue InGaN LEDs or a new generation of high power blue LEDs. The drivers of such LEDs may be implemented of avalanche transistors or a complementary pair of fast RF transistors. The most powerful and fast light sources utilize two or three consecutive avalanche transistors. It is shown that such light sources have light yields of up to 10**11-10**12 photons per pulse with a few nanosecond width of light pulses. The results of extensive studies of light emission kinetics of currently existing ultra bright LEDs are presented. It is shown that the light sources are very stable, reliable and robust. They are easily constructed and operated and very useful not only in calibration system but in laboratory test measurements of photodetctors.