Kim Ki-Han, Jin Hye-Jung, Park Kyoung-Ho, Lee Joun-Ho, Kim Jae Chang, Yoon Tae-Hoon
School of Electrical Engineering, Pusan National University, Busan 609-735, Korea.
Opt Express. 2010 Aug 2;18(16):16745-50. doi: 10.1364/OE.18.016745.
We propose a switchable achromatic reflector using a long-pitch cholesteric liquid crystal (CLC) whose Bragg reflection wavelength is chosen to be infrared by controlling the pitch of the CLC so that the planar texture is transparent over the entire visible wavelength. By using the light scattering of the focal conic texture, achromatic reflection can be achieved. Both textures are stable at zero electric field and the operating voltage of the proposed CLC device is much lower than that of conventional CLC devices. The proposed switchable reflector, which can be operated at a low voltage with low power, can be applied to reflective displays and to light shutters. By coupling with a reflective polarizer the efficiency of light scattering at the focal conic texture can be enhanced.
我们提出了一种使用长间距胆甾相液晶（CLC）的可切换消色差反射器，通过控制CLC的间距，将其布拉格反射波长选择为红外光，从而使平面织构在整个可见波长范围内都是透明的。利用焦锥织构的光散射，可以实现消色差反射。两种织构在零电场下都是稳定的，并且所提出的CLC器件的工作电压远低于传统CLC器件。所提出的可切换反射器可以在低电压下以低功耗运行，可应用于反射式显示器和光快门。通过与反射型偏振器耦合，可以提高焦锥织构处的光散射效率。
