基于液晶空间光调制器的复振幅全息显示进展

Recent progress in complex-modulated holographic display based on liquid crystal spatial light modulators

计算全息能够在计算机中实现光学全息的波前衍射计算与波前数字编码,并通过相干光照射全息图重建物光波前。但其空间带宽积受现有数字调制器件限制,光学重建受振幅编码或相位编码引入的噪声影响。复振幅全息利用现有的光电调控器件实现全息图复振幅波前编码,避免振幅项或相位项的损失,兼有高运算效率、高空间带宽积和高重建精度等优势。基于双相位的复振幅光场调控方法因其理论完备性高、光学系统方案成熟,在复振幅计算全息领域具有广阔的应用前景,是全息三维显示重要的发展方向。本文综述了复振幅计算全息的原理与研究进展,分析已报道的复振幅全息方案,重点介绍复振幅的双相位调制原理与基于双相位原理的液晶空间光调制器复振幅全息显示系统。

Computer-generated holography has shown the ability of diffractive calculation and digital encoding for optical wavefronts.The optical wavefronts can be reconstructed through the coherent illuminating onto computer-generated holograms.But the spatial bandwidth product of computer-generated holography is still limited by existing digital modulating elements,resulting in a degraded optical reconstruction with excessive noises introduced by amplitude encoding or phase encoding.Complex-modulated holography encodes the complex-amplitude wavefronts with existing optical elements and avoids the discarding of amplitude or phase.It possesses the advantages of high calculating efficiency,high spatial bandwidth product and high reconstructing accuracy.The double-phase decomposition is a promising complex-modulating method with high theoretical maturity and optical reliability,making it highly desired and of great value in the future three-dimensional holographic display.This paper reviews the principle and recent progress of complex-modulated holographic display,especially the recent researches based on the double-phase complex modulation using liquid crystal spatial light modulators.