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Yan X, Liu X, Li J, Zhang Y, Chang H, Jing T, Hu H, Qu Q, Wang X, Jiang X. Generating Multi-Depth 3D Holograms Using a Fully Convolutional Neural Network. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2308886. [PMID: 38725135 PMCID: PMC11267294 DOI: 10.1002/advs.202308886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 04/04/2024] [Indexed: 07/25/2024]
Abstract
Efficiently generating 3D holograms is one of the most challenging research topics in the field of holography. This work introduces a method for generating multi-depth phase-only holograms using a fully convolutional neural network (FCN). The method primarily involves a forward-backward-diffraction framework to compute multi-depth diffraction fields, along with a layer-by-layer replacement method (L2RM) to handle occlusion relationships. The diffraction fields computed by the former are fed into the carefully designed FCN, which leverages its powerful non-linear fitting capability to generate multi-depth holograms of 3D scenes. The latter can smooth the boundaries of different layers in scene reconstruction by complementing information of occluded objects, thus enhancing the reconstruction quality of holograms. The proposed method can generate a multi-depth 3D hologram with a PSNR of 31.8 dB in just 90 ms for a resolution of 2160 × 3840 on the NVIDIA Tesla A100 40G tensor core GPU. Additionally, numerical and experimental results indicate that the generated holograms accurately reconstruct clear 3D scenes with correct occlusion relationships and provide excellent depth focusing.
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Affiliation(s)
- Xingpeng Yan
- Department of Information CommunicationArmy Academy of Armored ForcesBeijing100072China
| | - Xinlei Liu
- Department of Information CommunicationArmy Academy of Armored ForcesBeijing100072China
- National Digital Switching System Engineering and Technological Research CenterZhengzhou450001China
- Information Engineering UniversityZhengzhou450001China
| | - Jiaqi Li
- Department of Information CommunicationArmy Academy of Armored ForcesBeijing100072China
| | - Yanan Zhang
- Department of Information CommunicationArmy Academy of Armored ForcesBeijing100072China
| | - Hebin Chang
- Department of Information CommunicationArmy Academy of Armored ForcesBeijing100072China
| | - Tao Jing
- Department of Information CommunicationArmy Academy of Armored ForcesBeijing100072China
| | - Hairong Hu
- Department of Information CommunicationArmy Academy of Armored ForcesBeijing100072China
| | - Qiang Qu
- Department of Information CommunicationArmy Academy of Armored ForcesBeijing100072China
| | - Xi Wang
- Department of Information CommunicationArmy Academy of Armored ForcesBeijing100072China
| | - Xiaoyu Jiang
- Department of Information CommunicationArmy Academy of Armored ForcesBeijing100072China
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Zhang N, Xiong B, Zhang X, Yuan X. High-capacity and multi-dimensional orbital angular momentum multiplexing holography. OPTICS EXPRESS 2023; 31:31884-31897. [PMID: 37859003 DOI: 10.1364/oe.499899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 08/29/2023] [Indexed: 10/21/2023]
Abstract
Optical holography has been investigated for enhancing information capacity and encryption. Here, the multi-vortex geometric orbital angular momentum (MVG-OAM) multiplexing holography is proposed and experimentally implemented, which encodes information into MVG beams with different central OAM, sub-beam OAM, and coherent-state phase. The orthogonality of the above three parameters are analyzed, respectively, which point out the feasibility of using them for holographic multiplexing. A three-dimensional multiplexing holography is realized by combining these three parameters, which offers potential applications for information storage, optical encryption, and display.
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3
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Shi Z, Wan Z, Zhan Z, Liu K, Liu Q, Fu X. Super-resolution orbital angular momentum holography. Nat Commun 2023; 14:1869. [PMID: 37015931 PMCID: PMC10073211 DOI: 10.1038/s41467-023-37594-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 03/16/2023] [Indexed: 04/06/2023] Open
Abstract
Computer-generated holograms are crucial for a wide range of applications such as 3D displays, information encryption, data storage, and opto-electronic computing. Orbital angular momentum (OAM), as a new degree of freedom with infinite orthogonal states, has been employed to expand the hologram bandwidth. However, in order to reduce strong multiplexing crosstalk, OAM holography suffers from a fundamental sampling criterion that the image sampling distance should be no less than the diameter of largest addressable OAM mode, which severely hinders the increase in resolution and capacity. Here we establish a comprehensive model on multiplexing crosstalk in OAM holography, propose a pseudo incoherent approach that is almost crosstalk-free, and demonstrate an analogous coherent solution by temporal multiplexing, which dramatically eliminates the crosstalk and largely relaxes the constraint upon sampling condition of OAM holography, exhibiting a remarkable resolution enhancement by several times, far beyond the conventional resolution limit of OAM holography, as well as a large scaling of OAM multiplexing capacity at fixed resolution. Our method enables OAM-multiplexed holographic reconstruction with high quality, high resolution, and high capacity, offering an efficient and practical route towards the future high-performance holographic systems.
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Affiliation(s)
- Zijian Shi
- Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Precision Space-time Information Sensing Technology, Beijing, 100084, China
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, Beijing, 100084, China
| | - Zhensong Wan
- Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Precision Space-time Information Sensing Technology, Beijing, 100084, China
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, Beijing, 100084, China
| | - Ziyu Zhan
- Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Precision Space-time Information Sensing Technology, Beijing, 100084, China
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, Beijing, 100084, China
| | - Kaige Liu
- Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Precision Space-time Information Sensing Technology, Beijing, 100084, China
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, Beijing, 100084, China
| | - Qiang Liu
- Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
- State Key Laboratory of Precision Space-time Information Sensing Technology, Beijing, 100084, China.
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, Beijing, 100084, China.
| | - Xing Fu
- Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
- State Key Laboratory of Precision Space-time Information Sensing Technology, Beijing, 100084, China.
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, Beijing, 100084, China.
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Pan J, Wang Z, Zhan Z, Fu X, Shen Y, Liu Q. Multiaxial super-geometric mode laser. OPTICS LETTERS 2023; 48:1630-1633. [PMID: 37221727 DOI: 10.1364/ol.485163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 02/19/2023] [Indexed: 05/25/2023]
Abstract
Structured light was usually studied by two-dimensional (2D) transverse eigenmodes. Recently, the three-dimensional (3D) geometric modes as coherent superposed states of eigenmodes opened new topological indices to shape light, that optical vortices can be coupled on multiaxial geometric rays, but only limited to azimuthal vortex charge. Here, we propose a new structured light family, multiaxial super-geometric modes, enabling full radial and azimuthal indices coupled to multiaxial rays, and they can be directly generated from a laser cavity. Exploiting combined intra- and extra-cavity astigmatic mode conversions, we experimentally verify the versatile tunability of complex orbital angular momentum and SU(2) geometry beyond the limit of prior multiaxial geometric modes, opening new dimensions to revolutionize applications such as optical trapping, manufacturing, and communications.
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Holographic Tailoring of Structured Light Field with Digital Device. PHOTONICS 2022. [DOI: 10.3390/photonics9070506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Structured light fields have attracted much attention due to rich spatial degrees of freedom. The tailoring of an arbitrary structured light field on demand is the precondition for the application of structured light. Therefore, the computer holography method used to reconstruct a coherent light field wavefront has been naturally applied for generating structured light. In this work, we comprehensively demonstrate the principles and procedures of pure-phase computer-generated holography (PP-CGH) and binary-amplitude computer-generated holography (BA-CGH) methods for tailoring structured light, realized by two digitally programmable devices: liquid-crystal spatial light modulators (Lc-SLM) and digital micromirror devices (DMD), respectively. Moreover, we first compare the two approaches in detail and clarify the recipe to obtain a high tailoring accuracy and efficiency, which will help researchers to better understand and utilize the holographic tailoring of structured optical fields.
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He C, Shen Y, Forbes A. Towards higher-dimensional structured light. LIGHT, SCIENCE & APPLICATIONS 2022; 11:205. [PMID: 35790711 PMCID: PMC9256673 DOI: 10.1038/s41377-022-00897-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 06/12/2022] [Accepted: 06/16/2022] [Indexed: 05/17/2023]
Abstract
Structured light refers to the arbitrarily tailoring of optical fields in all their degrees of freedom (DoFs), from spatial to temporal. Although orbital angular momentum (OAM) is perhaps the most topical example, and celebrating 30 years since its connection to the spatial structure of light, control over other DoFs is slowly gaining traction, promising access to higher-dimensional forms of structured light. Nevertheless, harnessing these new DoFs in quantum and classical states remains challenging, with the toolkit still in its infancy. In this perspective, we discuss methods, challenges, and opportunities for the creation, detection, and control of multiple DoFs for higher-dimensional structured light. We present a roadmap for future development trends, from fundamental research to applications, concentrating on the potential for larger-capacity, higher-security information processing and communication, and beyond.
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Affiliation(s)
- Chao He
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
| | - Yijie Shen
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Andrew Forbes
- School of Physics, University of the Witwatersrand, Private Bag 3, Johannesburg, 2050, South Africa.
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Wan Z, Shen Y, Wang Z, Shi Z, Liu Q, Fu X. Divergence-degenerate spatial multiplexing towards future ultrahigh capacity, low error-rate optical communications. LIGHT, SCIENCE & APPLICATIONS 2022; 11:144. [PMID: 35585043 PMCID: PMC9117247 DOI: 10.1038/s41377-022-00834-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 05/25/2023]
Abstract
Spatial mode (de)multiplexing of orbital angular momentum (OAM) beams is a promising solution to address future bandwidth issues, but the rapidly increasing divergence with the mode order severely limits the practically addressable number of OAM modes. Here we present a set of multi-vortex geometric beams (MVGBs) as high-dimensional information carriers for free-space optical communication, by virtue of three independent degrees of freedom (DoFs) including central OAM, sub-beam OAM, and coherent-state phase. The novel modal basis set has high divergence degeneracy, and highly consistent propagation behaviors among all spatial modes, capable of increasing the addressable spatial channels by two orders of magnitude than OAM basis as predicted. We experimentally realize the tri-DoF MVGB mode (de)multiplexing and data transmission by the conjugated modulation method, demonstrating lower error rates caused by center offset and coherent background noise, compared with OAM basis. Our work provides a potentially useful basis for the next generation of large-scale dense data communication.
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Affiliation(s)
- Zhensong Wan
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, 100084, Beijing, China
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, 100084, Beijing, China
| | - Yijie Shen
- Optoelectronics Research center, University of Southampton, Southampton, SO17 1BJ, UK
| | - Zhaoyang Wang
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, 100084, Beijing, China
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, 100084, Beijing, China
| | - Zijian Shi
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, 100084, Beijing, China
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, 100084, Beijing, China
| | - Qiang Liu
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, 100084, Beijing, China.
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, 100084, Beijing, China.
| | - Xing Fu
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, 100084, Beijing, China.
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, 100084, Beijing, China.
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Wan Z, Shen Y, Liu Q, Fu X. Multipartite classically entangled scalar beams. OPTICS LETTERS 2022; 47:2052-2055. [PMID: 35427334 DOI: 10.1364/ol.451046] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
Classically entangled light is used to refer to a class of structured beams with space-polarization, polarization-time, and space-time non-separable states akin to entangled states, which enable novel quantum-analog methods and applications in structured light. Here, we argue that classical entanglement is also available for pure scalar beams with multiple non-separable spatial degrees of freedom (DoFs). We theoretically and experimentally demonstrate a class of scalar ray-wave structured light with multiple controllable local DoFs to emulate multipartite entangled states, including the Greenberger-Horne-Zeilinger states. Our work unveils a rich parameter space for high-dimensional and multi-DoF control of structured light to extend applications in classical-quantum regimes.
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Volyar A, Akimova Y. Structural stability of spiral vortex beams to sector perturbations. APPLIED OPTICS 2021; 60:8865-8874. [PMID: 34613113 DOI: 10.1364/ao.435420] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
Conditions of breaking down the structural stability of a spiral vortex beam subject to sector perturbations were considered. Employing methods of computer simulation and processing experimental results, we have shown that the spiral vortex beam has a caustic surface, the intersection of which sharply changes a shape of the Poynting vector streamlines and critical points of the spiral beam. Nevertheless, the beam propagation (scaling and rotation) does not change the perturbed streamline's shape and phase pattern. We also revealed that strong beam perturbations can cause the conversion of the circulation direction of streamlines in the perturbation region, which entails the appearance of a network of optical vortices with negative topological charges. However, the beam's orbital angular momentum remains unchanging, despite increasing the information entropy (growing a number of vortex modes), so that the perturbed beam keeps new stable states.
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Babington J. Ray-wave duality of electromagnetic fields: a Feynman path integral approach to classical vectorial imaging. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2021; 38:817-826. [PMID: 34143151 DOI: 10.1364/josaa.424094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
We consider how vectorial aspects (polarization) of light propagation can be implemented and their origin within a Feynman path integral approach. A key part of this scheme is in generalizing the standard optical path length integral from a scalar to a matrix quantity. Reparametrization invariance along the rays allows a covariant formulation where propagation can take place along a general curve. A general gradient index background is used to demonstrate the scheme. This affords a description of classical imaging optics when the polarization aspects may be varying rapidly and cannot be neglected.
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Shen Y, Nape I, Yang X, Fu X, Gong M, Naidoo D, Forbes A. Creation and control of high-dimensional multi-partite classically entangled light. LIGHT, SCIENCE & APPLICATIONS 2021; 10:50. [PMID: 33686054 PMCID: PMC7940607 DOI: 10.1038/s41377-021-00493-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 05/25/2023]
Abstract
Vector beams, non-separable in spatial mode and polarisation, have emerged as enabling tools in many diverse applications, from communication to imaging. This applicability has been achieved by sophisticated laser designs controlling the spin and orbital angular momentum, but so far is restricted to only two-dimensional states. Here we demonstrate the first vectorially structured light created and fully controlled in eight dimensions, a new state-of-the-art. We externally modulate our beam to control, for the first time, the complete set of classical Greenberger-Horne-Zeilinger (GHZ) states in paraxial structured light beams, in analogy with high-dimensional multi-partite quantum entangled states, and introduce a new tomography method to verify their fidelity. Our complete theoretical framework reveals a rich parameter space for further extending the dimensionality and degrees of freedom, opening new pathways for vectorially structured light in the classical and quantum regimes.
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Affiliation(s)
- Yijie Shen
- School of Physics, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa.
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, 100084, Beijing, China.
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Isaac Nape
- School of Physics, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa
| | - Xilin Yang
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA, 90095, USA
| | - Xing Fu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, 100084, Beijing, China
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, 100084, Beijing, China
| | - Mali Gong
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, 100084, Beijing, China
- Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, 100084, Beijing, China
| | - Darryl Naidoo
- School of Physics, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa
- CSIR National Laser Centre, PO Box 395, Pretoria, 0001, South Africa
| | - Andrew Forbes
- School of Physics, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa.
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Wang Z, Shen Y, Naidoo D, Fu X, Forbes A. Astigmatic hybrid SU(2) vector vortex beams: towards versatile structures in longitudinally variant polarized optics. OPTICS EXPRESS 2021; 29:315-329. [PMID: 33362116 DOI: 10.1364/oe.414674] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
Structured light with more controllable degrees-of-freedom (DoFs) is an exciting topic with versatile applications. In contrast to conventional vector vortex beams (VVBs) with two DoFs of orbital angular momentum (OAM) and polarization, a hybrid ray-wave structure was recently proposed [Optica 7(7), 820-831 (2020)], which simultaneously manifests multiple DoFs such as ray trajectory, coherent state phase, trajectory combination, besides OAM and polarization. Here we further generalize this exotic structure as the astigmatic hybrid VVB by hatching a new DoF of astigmatic degree. Importantly, the transverse topology varies with propagation, e.g. a linearly distributed hybrid trajectory pattern can topologically evolve to a circularly polygonal star shape, where the number of singularity changes from zero to multiple in a single beam. The propagation-dependent evolution can be easily controlled by the astigmatic degree, including as a vector vortex state such that different astigmatic trajectories have different polarizations. We experimentally generate such beams from a simple laser with a special astigmatic conversion by combined spherical and cylindrical lenses, and the results agree well with our theoretical simulation. With our new structured light, the propagation-multiplexing multi-DoF patterns can be controlled in a single beam, which can largely extend related applications such as high-dimensional large-capacity optical communication, laser machining, and particle trapping.
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