光调谐胆甾相液晶激光器的研究

项目名称： 光调谐胆甾相液晶激光器的研究

项目编号： No.61308052

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 张伶莉

作者单位： 哈尔滨工业大学

项目金额： 26万元

中文摘要： 光调谐胆甾相液晶激光器具有体积小、线宽窄、阈值低、易于调谐等优点，在医学诊断、光发射二极管和显示等多方面有很好的应用前景。本课题提出采用金纳米颗粒键合的联二萘偶氮结构的光敏手性分子作为液晶手性剂，利用光照后偶氮结构和手性二面角的双重改变，增大胆甾相液晶激光器的光调谐范围，利用金纳米颗粒表面的等离子体增强效应，加快胆甾相液晶激光器的光调谐速率。进一步设计了相位补偿反射式双增益介质层的光调谐胆甾相液晶激光器结构，利用相位补偿减少胆甾相液晶谐振腔中光的损耗，利用反射式双胆甾相液晶层增大泵浦光的利用次数，以此来增大激光的发射强度，提高斜率效率，降低阈值。本课题的研究工作将促进光调谐胆甾相液晶激光器的发展，为其实用化提供研究基础。

中文关键词： 手性剂；胆甾相液晶；激光；纳米颗粒；光调谐

英文摘要： Optical tunable cholesteric liquid crystal (CLC) laser has a great application prospect in medical diagnostics, light-emitting diode, display etc., because of the microscopic size, narrow line width ,low threshold and easy to tuning. In this work,we design a liquid crystal chiral dopant with axially chiral 1,1'-binaphthyl group and the distinct optical properties of the azobenzene moiety, coated gold nanopaticles. The optical tuning range could be broadening by the double effect of azobenzene photoisomeration and chiral 1,1'-binaphthyl group. The optical tuning speed could be enhanced by the gold nanoparticle field enhancement effect of localized surface plasmons.Then we improve the threshold and slope efficiency using a new configuration, which includes sandwiching two dye doped cholesteric layers with a mirror reflector on one of the inner surfaces and two NLC phase retarder film. Two dye doped cholesteric layers and reflector increase the pumping efficiency. The phase retarder film decreases the optical loss in the cholesteric liquid crystal resonance cavity. These research work will accelarate the developement of the cholesteric liquid crystal laser, and provide the research fundation for the application.

英文关键词： chiral dopant；cholesteric liquid crystal；laser；nanoparticles；optical tunable