基于双拉曼池的氢气后向拉曼散射及放大

Backward Raman Scattering and Amplification Based on Dual Raman Cells

研究了基于双拉曼池的氢气后向受激拉曼散射及其放大特性。两个拉曼池内均充入高压氢气,前级拉曼池用于产生种子光,后级拉曼池用于实现种子光放大。测量了不同抽运光能量下的输出斯托克斯能量,以及抽运光能量在两拉曼池不同配比时的输出斯托克斯能量。当分配给前级拉曼池能量100 m J,后级拉曼池能量175 m J时,获得单脉冲44.0 m J的斯托克斯光,相应的光子转化率为28.6%。使用速率方程对拉曼放大部分进行了数值模拟,输出斯托克斯能量的理论值与实验值基本相符。数值模拟表明,在种子光能量等于或大于抽运光时,受激拉曼放大依然可以实现线性转化。根据模拟结果,提出了利用拉曼放大来实现多束激光串联合成输出的设想。

The characteristics of backward Raman scattering and amplification based on two hydrogen Raman cells are investigated. Both cells are filled with high-pressure hydrogen. The first cell is used to generate the Stokes seed light, and the second cell is used to amplify the seed light. The Stokes energy is measured at different pump energies,and different pump distributions between the two cells. When the pulsed pump energy of first and second cell separately is 100 m J, 175 m J, a pulsed Stokes energy of 44.0 m J can be generated, and the corresponding photon conversion efficiency is 28.6%. The rate equations are employed to simulate the amplification process, and the theoretical results are agree with the experimental results on the whole. When the pulsed energy of Stokes seed light is as much as or greater than the pump laser, the Stokes can still keep a constant increment according to the numerical simulation. Based on the simulation results, the Raman amplification method is proposed to realize multiple laser series synthetic output.