激光诱导等离子体对水团簇受激拉曼散射的影响

Influence of laser-induced plasma on Raman scattering of water cluster

利用532 nm脉冲激光作用于水分子,研究其受激拉曼Stokes和anti-Stokes散射.实验表明:激光束经过聚焦后,在能量为4 mJ时,水分子产生等离子体;在泵浦激光能量由5 mJ增加到15 mJ的过程中,水分子OH键伸缩振动的受激拉曼Stokes散射光强逐渐增大、受激谱带宽度逐渐加宽,并且受激拉曼Stokes散射中心波长呈现蓝移趋势;当能量为15 mJ时,产生了OH键伸缩振动的受激拉曼anti-Stokes散射光.利用激光诱导等离子体增强水分子团簇的受激拉曼散射理论解释了以上现象,实验与理论符合地很好.

The stimulated Raman Stokes and anti-Stokes scattering of water are studied with 532nm laser. The experi- mental results show that plasma of water is generated when the pump energy of laser is 4mJ. The intensity and bandwidth of the Stokes line OH stretching vibration are increased as the pump laser energies are increased from 5mJ to 15Mj, and the center wavelength of Stokes become blue-shifted. The anti-Stokes line of OH stretching vibration is generated when the pump laser energy is 15mJ. The enhancement of the stimulated Raman scattering of water cluster is well explained by the laser-induced plasma. These results show great promise＇for water as Raman laser media.