Phase Controlled Laser Interference for Tunable Phase Gratings in Dye-Doped Nematic Liquid Crystals

A phase controlled multi-beam interference is applied to excite the doped liquid crystals. Control of the phase difference between the exciting beams allows the external control of the interference pattern inside the liquid crystal. The dynamic variation of the grating is made possible with a time-dependent phase change to derive the nonlinear refractive index as well as the responding speed of the material. The induced grating structure is numerically modelled with reorientational phase gratings in the liquid crystal, and the diffraction dynamics is found to be in good agreement between theoretical and experimental results.     

共振吸收波导阵列的原理、特性、制备与应用

光子晶体、量子光学、超快光学与微纳光学的发展,使得操控光子的发射与传输特性成为可能.综述了具有复折射率周期性调制的共振吸收光子晶格,并着重介绍了共振吸收波导阵列的原理、光学特性、样品制备与应用.     

矢量光共焦扫描显微系统纳米标准样品的制备与物理测量精度

针对超分辨领域分辨率测量标准的缺失情况,本文介绍了一种用于纳米尺度分辨率测试的标准样品的设计方案和制备方法,该样品适用于矢量光共聚焦激光扫描显微系统.该设计方案包含一系列测量图案和明确的指示标记,具有测量范围宽、线宽梯级序列分布合理、制备精度高等特点.首先在非晶硅片上实现硅纳米标准样品的制备,并经过多次探索工艺,提高了测试图案的精度.光学测试结果证实该纳米标样可用于分辨率测试,同时测得矢量光共聚焦激光扫描显微镜的分辨率为96 nm (n=1.52, 405 nm光源).针对硅纳米标准样品低对比度的问题,本文提供石英片上金属纳米标准样品的制备方法作为补充.纳米标准样品的实现,为点扫描式超分辨显微镜的分辨率指标提供了一种更严谨的测试途径,同时能够为显微镜的调试提供原理性指导.测试中发现纳米尺度的光学成像效果除了受到样品形貌的影响外,还受到到样品的光电物性的影响,其相互作用机理尚待进一步深入研究.