Powerful light pulse formation in passive cavities

Possibilities of short light pulse formation using a controllable Fabri-Perot interferometer based an an optical fiber are considered. This controllable interferometer consists of four similar Bragg gratings which are set in a certain order in a fiber and which produce two interferometers. If the length of the first interferometer is 10mm and the length of the second one is 67mm, gratings reflection for Bragg wavelength equal 0.99 and when the power of 100W comes to such an interferometer in a fiber then it is possible to obtain 10(6) W power pulses with their duration of 0.64(.)10(-9) sec at period of repeats of 1.45(.)10(-5) sec at the output. Coefficient of efficiency is about 0.44.