Brillouin amplification of weak Stokes signal from sea water with different salinities and temperatures

A scheme is presented for amplifying weak Stokes signals from sea water with different salinities and temperatures by Brillouin amplification. CS₂ whose Brillouin shift is near to that of water´s is chosen as amplifier medium. A frequency doubled Nd:YAG laser is used to produce singlemode pulses of 7.2-ns duration. Results show that weak Stokes signals arising from water in the temperature range of 2°C to 40°C and salinity range of 0⁰/₀₀ to 35⁰/₀₀ can be amplified efficiently at room temperature. Signal gains as high as 10⁷ were achieved with input signal energy in the order of pJ in experiment.