聚合物分散液晶薄膜中随机激光辐射的实现

Realization of random lasing in polymer disperse liquid crystal film

设计制作染料掺杂聚合物分散液晶薄膜激光器件,研究随机激光辐射行为。利用微胶囊法将激光染料、向列相液晶、手性剂、聚乙烯醇混合,制备掺杂两种激光染料的聚合物分散液晶薄膜。利用输出激光532 nm的Nd:YAG倍频脉冲激光器进行泵浦,在582~607 nm波段获得尖锐、离散的随机激光输出,阈值能量约为9 m J,线宽约为0.3~0.4 nm。对于器件产生激光辐射的机制,利用环形腔理论进行了分析。对比掺杂单种激光染料的聚合物分散液晶薄膜激光器件,实验结果显示,同时混合不同类型的激光染料制备的聚合物分散液晶薄膜,能够实现较宽波段的随机激光输出。

Dye-doped polymer dispersed liquid crystal film was designed and fabricated, and the random laser action was studied. The mixture of laser dye, nematic liquid crystal, chiral dopant and PVA were used to prepare dye-doped polymer-dispersed liquid crystal by the method of microcapsule. Under frequency doubled 532 nm Nd : YAG( Yttrium Aluminum Garnet) laser- pumped optical excitation, a plurality of discrete and sharp random laser radiation peak can be measured in the range of 582-607 nm.The threshold of the random lasing is about 9 m J and the line-width is 0.3-0.4 nm. The theory of ring cavity is used to prepare dye-doped cholesteric liquid crystal laser. Comparison with doped one dye polymer dispersed liquid crystal film. The experimental results show that the polymer dispersed liquid crystal film of doped different types of laser dye, it is possible to achieve broad band random lasing.