基于液晶的多层湍流大气成像过程模拟技术研究

Although equiped with adaptive optics technology and the high-resolution image reconstruction method, the disturbation can not be removed completely from the telescopes because of the existence of atmospheric turbulence, which limits their high resolution.We aim at applying liquid crystal phase modulation technology on designing a multi-layer phase turbulence modulator with anisoplanatism and temporal coherence and related optical systems, of which their function is to modulate the phase of incident beam on different locations, to produce a wavefront similar with real turbulent atmosphere, and to realise the imaging process with an effect of turbulent atmosphere, such that we provide an experimental platform for investigating the adaptive optics and the high-resolution image reconstruction to promote their own performances in order to improve the resolution of telescopes. Our research involves the development of single liquid crystal turbulence modulator, the investigation of temporal coherence, the calibration of phase modulation, and the verification of its reliability, as well as a numerical simulation of the turbulent atmosphere. On the basis of this, we design an optical system based on multiple liquid crystal modulators to realise the anisoplanatism and temporal coherence of the turbulent atmosphere, and a simulation of turbulent atmospheric imaging process.

尽管配备了自适应光学技术和高分辨图像重建技术，但是由于湍流大气的存在天文望远镜依然不能完全消除湍流的干扰，使得高分辨率受到限制。项目旨在利用液晶相位调制技术设计具备非等晕性和时间相干效应的多层相位湍流模拟器及相关的光学系统，其功能是对入射光在不同位置进行相位调制，使之产生接近实际湍流大气扰动的波前相位，实现具有湍流大气干扰效应的成像过程，为自适应光学系统和高分辨图像重建技术的研究提供实验平台，使其提升自身性能进而提高天文望远镜的分辨率。研究内容涉及单层液晶湍流模拟器的研制、时间相干性研究、相位调制定标及其可靠性验证，同时进行了多层湍流大气的数值模拟研究。在此基础上，进行多层液晶模拟器的光学系统设计实现湍流大气的非等晕性及时间相干性，同时进行湍流大气成像过程模拟。

基于柯尔莫哥洛夫湍流理论，进行了湍流模拟的仿真软件编写，实现了不同湍流强度包括不同风速、不同相干长度的仿真模拟，对实验研究有指导意义。基于液晶的调谐特性以及PBA材料对pH值敏感的原理，利用5CB液晶掺杂PBA的液晶微滴，研究了pH值的传感以及盘尼西林的水解检测工作。在光纤端面实现了液晶法˙玻腔的温度传感探头设计及制备，利用液晶的双折射特性，用单一的法˙玻腔获得了干涉光谱的游标效应，实现了大的自由光谱范围和高温度灵敏度（19.55 nm/°C）的温度传感。同时，利用该原理实现了位移传感，灵敏度达到2.97 nm/μm。利用液晶包覆的二氧化硅微球，实现带隙激光及回音壁激光的双重激发及控制，研究了温度响应特性研究。利用胆甾相液晶的手性螺旋特性，在微型毛细管内实现了激光发射的温度控制。开展了液晶填充光子晶体光纤的温度传感方面的研究，实现了光传输的温度控制。研究结果有望在生物传感领域获得应用。同时对其在DNA、杨梅素、蛋白质及活性细胞的探测工作上具有指导意义。在微观尺度的温度探测上有潜在应用，如：细胞、病毒的温度探测上等。