Brillouin Distributed Fiber Sensors: An Overview and Applications
Figure 8
The pump light is basically formed by a pump-prepump pair pulse, and by subtracting the couple Brillouin backscattering it is possible to use larger base pulses to obtain stronger backscattered signals or to reach larger distances in the fiber. (a) Experimental data of preexcitation optical pulse. (b) Experimental data for 2 ns of main pulse and four values of P-pulse. Brillouin spectrum gain (inset figure).
