This Letter describes an approach to encode complex-amplitude light waves with spatiotemporal double-phase holograms(DPHs) for overcoming the limit of the space-bandwidth product(SBP) delivered by existing methods. To...This Letter describes an approach to encode complex-amplitude light waves with spatiotemporal double-phase holograms(DPHs) for overcoming the limit of the space-bandwidth product(SBP) delivered by existing methods. To construct DPHs, two spatially macro-pixel encoded phase components are employed in the SBP-preserved resampling of complex holograms. Four generated sub-DPHs are displayed sequentially in time for high-quality holographic image reconstruction without reducing the image size or discarding any image terms when the DPHs are interweaved. The reconstructed holographic images contain more details and less speckle noise, with their signal-to-noise ratio and structure similarity index being improved by 14.64% and 78.79%,respectively.展开更多
Computer-generated holography is a promising technique that modulates user-defined wavefronts with digital holograms.Computing appropriate holograms with faithful reconstructions is not only a problem closely related ...Computer-generated holography is a promising technique that modulates user-defined wavefronts with digital holograms.Computing appropriate holograms with faithful reconstructions is not only a problem closely related to the fundamental basis of holography but also a long-standing challenge for researchers in general fields of optics.Finding the exact solution of a desired hologram to reconstruct an accurate target object constitutes an ill-posed inverse problem.The general practice of single-diffraction computation for synthesizing holograms can only provide an approximate answer,which is subject to limitations in numerical implementation.Various non-convex optimization algorithms are thus designed to seek an optimal solution by introducing different constraints,frameworks,and initializations.Herein,we overview the optimization algorithms applied to computer-generated holography,incorporating principles of hologram synthesis based on alternative projections and gradient descent methods.This is aimed to provide an underlying basis for optimized hologram generation,as well as insights into the cuttingedge developments of this rapidly evolving field for potential applications in virtual reality,augmented reality,head-up display,data encryption,laser fabrication,and metasurface design.展开更多
基金supported by the National Natural Science Foundation of China (NSFC)(Nos. 61827825 and 61775117)Tsinghua University Initiative Scientific Research Program (No. 20193080075)the Cambridge Tsinghua Joint Research Initiative
文摘This Letter describes an approach to encode complex-amplitude light waves with spatiotemporal double-phase holograms(DPHs) for overcoming the limit of the space-bandwidth product(SBP) delivered by existing methods. To construct DPHs, two spatially macro-pixel encoded phase components are employed in the SBP-preserved resampling of complex holograms. Four generated sub-DPHs are displayed sequentially in time for high-quality holographic image reconstruction without reducing the image size or discarding any image terms when the DPHs are interweaved. The reconstructed holographic images contain more details and less speckle noise, with their signal-to-noise ratio and structure similarity index being improved by 14.64% and 78.79%,respectively.
基金supported by the National Science Foundation of China(62035003)the Tsinghua University Initiative Scientific Research Program(20193080075)as well as the Cambridge Tsinghua Joint Research Initiative。
文摘Computer-generated holography is a promising technique that modulates user-defined wavefronts with digital holograms.Computing appropriate holograms with faithful reconstructions is not only a problem closely related to the fundamental basis of holography but also a long-standing challenge for researchers in general fields of optics.Finding the exact solution of a desired hologram to reconstruct an accurate target object constitutes an ill-posed inverse problem.The general practice of single-diffraction computation for synthesizing holograms can only provide an approximate answer,which is subject to limitations in numerical implementation.Various non-convex optimization algorithms are thus designed to seek an optimal solution by introducing different constraints,frameworks,and initializations.Herein,we overview the optimization algorithms applied to computer-generated holography,incorporating principles of hologram synthesis based on alternative projections and gradient descent methods.This is aimed to provide an underlying basis for optimized hologram generation,as well as insights into the cuttingedge developments of this rapidly evolving field for potential applications in virtual reality,augmented reality,head-up display,data encryption,laser fabrication,and metasurface design.
