碳纳米管悬浮液对532nm激光限幅机理的实验研究

Optical limiting mechanism of suspended carbon nanotubes

通过光限幅、Z扫描、非线性吸收和散射能量分布实验,研究了碳纳米管悬浮液对532 nm激光的限幅机理以及样品厚度对光限幅机理的影响。结果表明:碳纳米管悬浮液的光限幅机理并非单纯的非线性散射,对低能量入射激光光限幅特性主要源于对入射激光的非线性吸收;对高能量入射激光,碳纳米管的吸收效应和它电离形成的微等离子体以及液体汽化所形成气泡散射效应的共同作用,使其具有较强的光限幅能力,对浓度一定的悬浮液,增加样品厚度虽然会增强其限幅效果,但却会减弱其非线性散射效应。

Both the optical limiting mechanism of suspending liquid of multi-walled carbon nanotubes for 532nm laser and the impact of sample＇s thickness on limiting mechanism were investigated by Zscan test,nonlinear absorption test and nonlinear scattering test.The results show that nonlinear absorption is the main reason in optical limit for lower input energy.Nonlinear absorption of carbon nanotubes,nonlinear scattering of plasma generated by ionization and air bubble generated by solvent boiloff result in a strong limiting factor of carbon nanotubes for high input energy.With the increase of sample thickness,the limiting factor of carbon nanotubes increases, but its nonlinear scattering is reduced when the concentration of suspending liquid is fixed.