基于多空间光调制器拼接的空间悬浮全息真三维显示

Multi-Spatial Light Modulator Splicing-Based Real 3D Display of Spatially Suspended Holography

全息技术是实现空间悬浮真三维(3D)显示的重要方法。空间光调制器(SLM)作为当前唯一的实时动态全息真3D图像投射仪器,像素量、分辨率等不足限制了其在空间悬浮真三维显示领域的应用。研究多SLM拼接实现高分辨低噪声的空间悬浮真3D显示,首先通过菲涅耳层析法结合空间坐标变换技术,计算获得3D物体360°视角的高分辨率全息图;然后将每张全息图分为相同分辨率的4幅图,加载到阵列式拼接的4个SLMs上,滤除一阶之外的光束后,再现出完整的具有高信息容量高分辨率的全息3D实像;最后利用超声雾化介质进行承载,实现实时动态空间悬浮真3D显示。另外,利用时间平均法对重建像进行噪声抑制研究,实验结果证明该方法可有效地提升空间悬浮全息显示图像的质量。

Holographic technology is crucial for realizing a true three-dimensional(3D) display of space suspension.The spatial light modulator(SLM) is currently the only device capable of real-time dynamic holographic true 3D image projection.However,the lack of pixels and resolution limits its application in the field of space suspended true 3D displays.This study examines the real 3D display of space suspension with high resolution and low noise realized using multi-SLM splicing.First,the high resolution hologram with the 360° viewing angle of a 3D object was calculated by Fresnel tomography combined with the spatial coordinate transformation technology.Then,each hologram was divided into four pieces of the image with the same resolution,which were loaded onto four SLMs spliced in an array.After filtering the light beams other than the first order,a complete holographic 3D real image with high information capacity and resolution was reconstructed.Finally,the ultrasonic atomized medium was used for carrying the 3D real image,realizing real-time dynamic space suspension true 3D display.Additionally,this study investigates the noise suppression for the reconstructed image using the time-averaged method,and the experimental results prove that this method can effectively improve the quality of the spatially suspended holographic display image.