True time delay using optical Stimulated Brillouin scattering

An electrical time delay structure using optical Stimulated Brillouin scattering is proposed. The system uses a stimulated 2nd Stokes wave as the signal wave and a stimulated 1st Stokes wave as Brillouin pumping to reduce coupling mismatch of frequency in Brillouin gaining process and to simplify the structure. The delay time between the system´s electrical output and input can be easily tuned by adjusting the attenuation ratio of the system´s variable optical attenuator. As a result, a tuning range from 13.8ns to 22.2 ns is achieved when the frequency of input electrical signal is 50 MHz, and from 3.5 ns to 7.9 ns when the frequency of input electrical signal is 80 MHz.