模板化蓝相液晶多波长滤波器

Multi-wavelength filters of templated blue phase liquid crystal

胆甾相液晶被广泛应用于光学滤波器中,但是其带宽较宽,无法应用于窄带宽滤波器。而蓝相液晶滤波器反射带宽窄,且其在聚合前后以及模板化重构前后稳定性非常好。因此,本文研究模板化单畴蓝相液晶的制成与光特性,通过多模板集成,可以实现多波长窄带滤波器的灵活制备。实验结果表明:单畴蓝相液晶的中心反射波长的半高宽约为35 nm,比胆甾相液晶的反射带宽要窄得多,并且模板化过程中心波长与带宽基本保持不变。且当入射角变化时,模板化蓝相液晶滤波器的中心波长偏移也远小于胆甾相液晶滤波器。用这种方法实现的滤波器具有很高的稳定性和可重复性。

Cholesteric liquid crystals(CLCs)are widely used in optical filters,but their bandwidth is too wide to be used in narrow bandwidth filters.The reflection bandwidth of blue phase liquid crystal(BPLC)filter is narrower than that of CLCs and the filter shows good stability before and after polymerization and templated process.Therefore,the fabrication and optical properties of templated mono-domain blue phase liquid crystals are investigated in this paper.By multi-template integration,the flexible fabrication of narrowband multi-wavelength filters can be achieved.The experimental results show that the full width at half maximum(FWHM)of the central reflection wavelength of mono-domain blue-phase liquid crystals is about 35 nm,which is much narrower than that of cholesteric liquid crystals,and the central wavelength would not shift during the template process,and the corresponding bandwidth remains unchanged.While the incident angle changes,the shift of center wavelength of the template blue-phase liquid crystal filter is much smaller than that of the cholesteric liquid crystal filter.The filter realized by this method exhibits high stability and repeatability.