中文摘要：

研究了激光染料若丹明6G（R6G）在乙基氰乙基纤维素[（E—CE）C]／N烯酸（AA）胆甾型液晶溶液中的随机激光行为。发现在没有添加任何固体散射粒子的情况下，在（ECE）C／AA／R6G溶液中观察到多个分离激光峰，最小半峰全宽（FWHM）为0．3nm．表现出相干反馈行为。这种相干反馈激光行为的形成可能与液晶溶液中胆甾型微区的选择性反射和其折光指数各向异性密切相关。

英文摘要：

Random lasing action of rhodamine 6G （R6G） in ethyl-cryanoethyl cellulose [-（E-CE）C]/acrylic acid （AA） cholesteric liquid crystal （LC） solution without doping fine powder was firstly studied. It is found that random laser with coherent feedback occurrs in the LC solutions, while only narrowing spectra phenomenon was observed in isotropic （E-CE）C/AA solution and AA solvent. And the narrowest full wavelength at half-maximum （FWHM） of laser peak is 0.3 nm. The laser threshold changes from 27 μJ to 20 μJ when the concentration of （ECE）C/AA solution varies from 35% to 46.5%. This random laser with coherent feedback is related to the multiple scattering resulting from the selected reflection and low diffusion constant in LC solution.