单模光纤中受激布里渊散射对纳秒激光脉冲的光限幅特性

Optical Limiting of Nd∶YAG Nanosecond Laser Pulses by Stimulated Brillouin Scattering in Single-mode Fiber

采用 2m长 ,10 0 μm纤径单模光纤 ,研究了受激布里渊散射对纳秒激光脉冲的光限幅特性。从耦合波方程出发 ,利用计算机模拟了光纤中瞬态受激布里渊散射过程的光传输特性。理论模拟的能量及光强度的变化规律表明光纤系统对纳秒激光具有很好的光限幅特性。根据理论分析给出所讨论范围内的实验结果 ,实验结果证明此光学系统对纳秒激光脉冲具有光限幅特性及脉宽压缩特性 ,对于输入能量在 10 0～ 4 0 0 μJ变化的纳秒激光脉冲 ,给出输出能量稳定在 6 5～ 85 μJ范围内 。

In this paper, optical limiting effect is studied based on the stimulated Brillouin scattering (SBS) in a single-mode fiber. Nonlinear propagation has been numerically analyzed and computationally treated in the transient SBS progress. Optical limiting, stabilization and output pulse shape have been demonstrated when high-power laser pulses enter a fiber when SBS occurs. Experimental investigation of optical limiting performances predicted by theory has been conducted using a 100 μm-diameter fiber. The input optical signals are Nd∶YAG nanosecond laser pulses which widths are 16 ns, superior constant output energy was gained when the intensity of input pulse change in experimental regime. When the input energy varied between 100～400 μJ, the fiber system gives relative stable output energy between 65～85 μJ. So the experiment results showed the optical limiting performance based on SBS in a fiber.