Phase matching for noncollinear Brillouin amplification based on controlling of frequency shift of Stokes seed

A method to compensate phase detuning, which will lead to the low efficiency in noncollinear Brillouin amplification by controlling the frequency shift of Stokes seed, is proposed. The efficiency of noncollinear Brillouin amplification can be sustained at the level of collinear Brillouin amplification for a large crossing angle. For crossing angles between Stokes and pump of 20° and 35°, the Brillouin gain coefficient is improved 1.24 and 4.93 times, accordingly.