快响应掺铋铌酸锂晶体及其实时动态全息3D显示的研究

Real-time dynamic holographic 3D display attracts great attention of each and every concerned country, owing to its wide application prospects in Military, Medical, Entertainment, and other fields. Lithium niobate (LiNbO3, LN) crystal, as the classical holographic medium, is limited in holographic 3D real-time dynamic display for two critical factors: long response time and low diffraction efficiency，meanwhile, the response time remains in millisecond level at continuous visible wavelength. The Bi3+ possesses electron lone pair, the response time of bismuth-doped LN (LN:Bi) crystal reduce to 50 ms, and the saturated diffraction efficiency is up to 26%. The bismuth-doped LN crystal can realize quasi real-time dynamic holographic display at 10 frame per second..The project is dedicated to research the relations between the LN crystal photorefraction properties and the following factors: the different doping components, polarization conditions, oxidation\reduction status, the laser wavelength and power intensity. Using the effective control technique, the response time can be shortened to less than 20 ms with high diffraction efficiency. Employ the angle and spatial multiplexing technology, the bismuth-doped LN crystal realize Real-time dynamic holographic 3D display. The microscopic mechanisms of the photorefraction enhancement in the bismuth-doped crystals will be researched. The growth process will be optimized to grow high quality, large size bismuth-doped LN crystals that can be used for real-time dynamic holographic 3D display. The project is expected to expand the control technique of the bismuth-doped LN crystal photorefraction properties, and solve the fundamental problems of LN crystal in the real-time holographic 3D display.

实时动态全息3D显示在军事、医疗、娱乐等领域广阔的应用前景引起各国极大关注。铌酸锂（LiNbO3,LN）晶体是经典的全息介质，响应时间长、衍射效率低是限制其实时动态全息3D显示的关键因素，在连续可见光波段响应时间仍停留在百毫秒量级。Bi3+核外具有立体化学活性的孤对电子，掺铋LN晶体响应时间缩短到50ms以内，饱和衍射效率达26%，可实现10帧/秒的准实时动态全息显示。.本项目研究掺铋LN晶体光折变性能与掺杂组分、极化条件、氧化\还原状态、激光波长及功率密度的关系,有效调控其响应时间缩短到20ms以内并保持高饱和衍射效率；参考角度、空间复用技术，实现掺铋LN晶体实时动态全息3D显示；探明掺铋LN晶体光折变效应增强的微观机制；优化LN晶体生长工艺，生长实时动态全息3D显示可用高质量、大尺寸掺铋LN晶体，以期拓展LN晶体的性能调控技术，解决LN晶体用于实时动态全息3D显示的基础性问题。

三维（3D）显示能够完整展现物体的振幅和相位信息，带给人们前所未有的临场感，已在影视娱乐领域率先获得成功，同时在虚拟现实（AR）和增强显示（VR）领域也表现出巨大的应用前景和经济价值。基于光折变材料的实时动态全息三维显示依然是目前研究的热点，本项目围绕提高LN晶体的光折变响应及其动态全息3D显示的目标，开展了系列新型掺杂LN晶体的生长及在可见光波段的光折变性能研究；在连续可见光波段，选择快响应的铋镁双掺LN晶体开展了动态全息显示研究；基于第一性原理计算对掺杂LN晶体性能调控的微观机制开展研究工作，最后开展了大尺寸、高质量双掺LN晶体的生长研究。通过本项目实施将掺铋LN晶体的响应时间在351nm缩短到4.8ms，在442nm 缩短到12ms，饱和衍射效率分别为42%，27%；提出双电子激发俘获模型明确了掺铋LN晶体光折变性能提高的微观机制，成功生长了2英寸铋镁双掺LN晶体。发表SCI论文13篇，授权国家专利3项，培养研究生4名。本项目按照计划顺利开展，达到了目标要求，为基于光折变材料LN晶体开展应用研究奠定基础。