QUARTZ FIBER PHASE CONJUGATORS WITH HIGH-FIDELITY AND REFLECTIVITY

Phase conjugators based on stimulated Brillouin scattering in undoped multimode quartz fibres can be operated with high fidelity and reflect ivity. The threshold, reflectivity and fidelity of fibres with a core diameter of 200 mu m and different lengths were measured with 30 ns pu lses at 1.06 mu m wavelength with different coherence lengths of the i nput beams. The depolarization of SBS pulses could be reduced to less than 0.5% by proper configuration of the fibre. Such fibre phase conju gators operate with more than 50% reflectivity, 93% fidelity, and less than 17 kW threshold.