Brillouin amplification of weak stokes signals from water based on a double-stage non-collinear system with mixture medium

摘要

A scheme is presented for amplifying weak Stokes signals from water using mixture medium of CS2/CCl4 in a double-stage non-collinear Brillouin amplification system. A frequency doubled Nd:YAG laser is used to produce single-mode pulses of 5.5-ns duration. Results show that choosing mixture liquid of CS2/CCl4 as amplifier medium has advantages over pure CS2. Maximum gain can be obtained by changing the mixed ratio of medium to eliminate the difference of the Brillouin frequency shift between the generator and amplifier. Signal gain as high as 1011 is experimentally achieved with an input signal of 8.6×10−14J using the mixture of 90% CS2 and 10% CCl4 as the amplifier medium.