Fig 1 Design of the disordered metasurface and its operation principle.
Published:31 July 2024,
Published Online:04 June 2024,
Received:12 December 2023,
Revised:25 April 2024,
Accepted:15 May 2024
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Optical information transmission is vital in modern optics and photonics due to its concurrent and multi-dimensional nature, leading to tremendous applications such as optical microscopy, holography, and optical sensing. Conventional optical information transmission technologies suffer from bulky optical setup and information loss/crosstalk when meeting scatterers or obstacles in the light path. Here, we theoretically propose and experimentally realize the simultaneous manipulation of the coherence lengths and coherence structures of the light beams with the disordered metasurfaces. The ultra-robust optical information transmission and self-reconstruction can be realized by the generated partially coherent beam with modulated coherence structure even 93% of light is recklessly obstructed during light transmission, which brings new light to robust optical information transmission with a single metasurface. Our method provides a generic principle for the generalized coherence manipulation on the photonic platform and displays a variety of functionalities advancing capabilities in optical information transmission such as meta-holography and imaging in disordered and perturbative media.
Information transmission plays a vital role in both theoretical physics and applied technology. In the past decades, optical information transmission has gathered great interest due to its concurrent and multi-dimensional nature
Originating from the local or extended optical resonances that depend on both the constituent materials and geometric designs of the nanostructures, metasurfaces can achieve efficient optical manipulation from near-fields to far-fields
Here, taking advantage of the global correlation provided by spatial coherence manipulation
Based on the optical statistics theory, the spatial coherence is a second-order statistical property describing the correlation between two spatial points of the random light fields. The characteristics of spatial coherence are calculated by the degree of coherence (DOC) function
1
where
2
where
3
The phase fluctuation of
With the ability of metasurfaces to accurately engineer the wave-front of light beams
Fig 1 Design of the disordered metasurface and its operation principle.
a The incident light passing through the disordered metasurface with a modified coherence structure and generating source speckles. With a scattering barrier blocking out the optical transmission, the far-field speckles are obtained. b The unit cell of the designed nanofin with disorder-engineered orientation set {θdis}. c The coherence structure obtained from the source speckles in a. d The statistical intensity statistically obtained from the far-field speckles, containing the transmitted optical information with (top) and without (bottom) the barrier
A proof-of-concept design to demonstrate the proposed strategy is shown in
4
5
Fig 2 Correlation between the DOC and the disordered metasurface design.
a Diagram of the synthesis of the transmitted function T of the disordered metasurface. b, c Intensity (top) and phase (bottom) distributions on the metasurfaces to manipulate spatial coherence with various prescribed DOC (HG22 in b, LG5 in c). The coherence lengths are 25 μm (left) and 10 μm (right). d An illustration of the spatial coherence manipulation with the metasurface. The spatial correlation of the instantaneous intensity distributions at the source plane determines the DOC of the average intensity transmitted from the metasurface
where
Fig 3 Spatial coherence structures manipulated by the disordered metasurface and propagation properties of the generated beams.
a A right-handed circularly polarized incident light is focused on the metasurface, and the transmitted left-handed circularly polarized light can be collected by an objective paired with a tube lens. The propagation planes at different zn are imaged by an imaging system to capture instantaneous intensity distributions at the source plane and far-fields. b SEM images of the fabricated metasurface. c, d The spatial coherence structure and far-field intensity distributions of the HG22-correlated (c) and LG5-correlated (d) beams customized in theory (top) and their measured counterparts (bottom)
The spatial coherence structure determines the light distribution of the beams in the far-field. Such spatially distributed fields can carry transportable optical information of the metasurfaces. As shown in the right columns of
We further experimentally demonstrate the self-reconstruction of the HG01-correlated Schell-model beams with coherence lengths of δ0 = 10 μm and δ0 = 25 μm (
Fig 4 Experimental self-reconstruction of the HG01-correlated beam blocked by a sector-shaped opaque object.
a Schematic of the self-reconstruction and intensity distributions of the partially coherent beams manipulated by the metasurface. b The theoretical cut-lines of the intensity distributions of the obstructed and unobstructed beams. c Dp as a function of the coherence length of the HG01-correlated Schell-model beams obstructed by different sector-shaped opaque objects. d Intensity distributions for the unobstructed and α = 3/2π obstructed optical transmission at the z = 0 plane. e, f Intensity distributions of the beams at the focal plane for unobstructed and α = 3/2π obstructed optical transmission with a coherence length of 10 μm (e) and 25 μm (f)
We further demonstrate the proposed strategy also enables self-reconstructed imaging with the designed disordered metasurfaces (
Fig 5 Self-reconstructed imaging by metasurface based on spatial coherence structures engineering.
The target image 'Panda' (a) and 'Meta' (b) to design the metasurface and the corresponding DOC distribution (top). (ⅰ)-(ⅳ): the intensity distributions at the focal plane with different obstacles
The proposed scheme not only simplifies the spatial coherence manipulation setup but also significantly improves the compactness and performance. Compared with conventional methods to manipulate the degree of spatial coherence such as the combination of the rotating ground glass disk and SLM, our strategy provides more accurate manipulation of speckle distributions with high efficiency due to the subwavelength nature. Compared with conventional informational strategies such as holography, which also enables global information encoded to the localized areas, our strategy provides robustness against scatterers and disturbance during light transmission owing to the statistical property. Note that the ratio of obstructed light can be further increased even approaching 100%, as long as the DOC is sufficiently small and the signal-to-noise ratio is experimentally guaranteed. Compared with conventional diffractive optical elements (DOE), the disordered metasurfaces can enable higher efficiency and resolution in information transmission, shorter coherence length and faster convergence during the wave propagation, which benefit further applications in integrated optical manipulation and coherence steering at micro-nanoscale. The resolution of the reconstructed image is closely related to the coherence length of partially coherent beams. If the coherence length is sufficiently low, the resolution is mainly limited by the diffraction limit. Moreover, the design strategy to manipulate the spatial coherence proposed here is not only limited to the specific beams mentioned in this work. Arbitrary Schell-model light beams can be generated by the metasurface, which can carry different information by their spatial coherence structures. Our approach can also be potentially expanded to carry dynamic information taking advantage of the versatile local optical resonances of metasurfaces, which may enable multiplexing of serial ensemble averages
In summary, we have proposed a strategy to simultaneously manipulate the spatial coherence structure and coherence length of the light beams based on disordered metasurfaces. By loading a random wave-front with a specific correlation function, the proposed metasurface can accurately manipulate the incident beams with a predefined spatial coherence structure and coherence length, and the experimental results are consistent with the theoretical calculations. Our strategy enables a wide branch of partially coherent beams with arbitrarily designed coherence lengths, such as HGCSM beams and LGCSM beams. We have demonstrated the robust optical information transmission and self-reconstruction with the disordered metasurface even if most of the light is recklessly obstructed during light transmission, which might shed new light on optical information transmission in disordered and perturbative media. Our scheme provides a generic principle for the generalized coherence manipulation and paves the way towards a plethora of applications in robust holography, optical computation and beam steering.
The dielectric disordered TiO2 metasurfaces were manufactured on a meticulously prepared fused silica substrate. Initially, a 550 nm layer of electron-beam resist (specifically, ZEP 520 A by Zeon) was uniformly applied to the substrate using a spin-coating process. This coated substrate was then subjected to a hot plate treatment at 180 ℃ for a duration of 1 min. To prevent any electric charge buildup during the subsequent electron-beam writing step, a thin layer of E-spacer 300Z (Showa Denko) was applied atop the resist layer. The precise nanostructures were defined through electron-beam lithography, specifically employing a Raith150 instrument operating at 30 kV with a current of 20 pA and a dose of 80 μC/cm2. Subsequently, the exposed structures were developed in an n-amyl acetate solvent at room temperature for a period of 60 s. A conformal layer of TiO2, with an approximate thickness of 70 nm, was deposited onto the substrate using an atomic layer deposition system (Picosun). This deposition process involved the use of titanium tetrachloride and H2O as precursor materials within a reactor maintained at a temperature of 130 ℃. Following the deposition, a blank-etching procedure of the TiO2 layer was carried out using CHF3 plasma within an inductively coupled plasma-reactive ion etching (ICP-RIE) system. Under controlled conditions, the TiO2 layer was etched until the underlying ZEP 520 A resist was exposed. These etching conditions involved the use of 20 sccm of CHF3, with a bias power of 20 W and an induction power of 500 W, all within an operating pressure of 10 mTorr. This process resulted in an etching rate of approximately 40 nm per minute for the TiO2 layer. Finally, O2 plasma with a minor addition of CHF3 was used to fully remove the remaining ZEP resist.
This work was supported by the National Key Research and Development Program of China (2022YFA1404800, 2021YFA1400601), the National Natural Science Fund for Distinguished Young Scholar (11925403), the National Natural Science Foundation of China (12122406, 12192253, 12192254, 92250304, 12304365), Natural Science Foundation of Tianjin City (22JCYBJC00800, 22JCZDJC00400), the China Postdoctoral Science Foundation (2022M721993), and the 111 Project (B23045). Fabrication work was carried out at the ACT node of the Australian National Fabrication Facility.
L.L., W.L., Y.C. and S.C. initiated the idea. L.L., W.L., F.W., X.P. and H.C. performed the theoretical analysis, numerical simulations and experiments. D.C. fabricated the samples. L.L., W.L., X.P., H.C., Y.C. and S.C. prepared the manuscript. Y.C. and S.C. supervised the project. All the authors contributed to the analyses and discussions of the manuscript.
The data that support the finding of this study are available from the corresponding author upon request.
The authors declare no competing interests.
Supplementary information The online version contains supplementary material available at https://doi.org/10.1038/s41377-024-01485-3.
Ding, Y. et al. Metasurface-dressed two-dimensional on-chip waveguide for free-space light field manipulation.ACS Photonics9, 398–404 (2022).. [Baidu Scholar]
Zhang, Y. B. et al. On-chip multidimensional manipulation of far-field radiation with guided wave-driven metasurfaces.Laser Photonics Rev.17, 2300109 (2023).. [Baidu Scholar]
Cheng, K. X. et al. Super-resolution imaging based on radially polarized beam induced superoscillation using an all-dielectric metasurface.Opt. Express30, 2780–2791 (2022).. [Baidu Scholar]
Dong, B. W. et al. Biometrics-protected optical communication enabled by deep learning–enhanced triboelectric/photonic synergistic interface.Sci. Adv.8, eabl9874 (2022).. [Baidu Scholar]
Li, X. et al. Independent light field manipulation in diffraction orders of metasurface holography.Laser Photonics Rev.16, 2100592 (2022).. [Baidu Scholar]
Yesharim, O. et al. Direct generation of spatially entangled qudits using quantum nonlinear optical holography.Sci. Adv.9, eade7968 (2023).. [Baidu Scholar]
Cheng, J. W., Zhou, H. L.&Dong, J. J. Photonic matrix computing: from fundamentals to applications.Nanomaterials11, 1683 (2021).. [Baidu Scholar]
Wang, F. et al. Far-field super-resolution ghost imaging with a deep neural network constraint.Light Sci. Appl.11, 1 (2022).. [Baidu Scholar]
Wu, H. et al. Deep-learning denoising computational ghost imaging.Opt. Lasers Eng.134, 106183 (2020).. [Baidu Scholar]
Klug, A., Peters, C.&Forbes, A. Robust structured light in atmospheric turbulence.Adv. Photonics5, 016006 (2023).. [Baidu Scholar]
Lu, L., Joannopoulos, J. D.&Soljačić, M. Topological photonics.Nat. Photonics8, 821–829 (2014).. [Baidu Scholar]
Zhang, Y. H. et al. Realization of photonicp-orbital higher-order topological insulators.eLight3, 5 (2023).. [Baidu Scholar]
Nagulu, A. et al. Chip-scale Floquet topological insulators for 5G wireless systems.Nat. Electron.5, 300–309 (2022).. [Baidu Scholar]
Yang, H. et al. Angular momentum holography viaa minimalist metasurface for optical nested encryption.Light Sci. Appl.12, 79 (2023).. [Baidu Scholar]
Resisi, S., Popoff, S. M.&Bromberg, Y. Image transmission through a dynamically perturbed multimode fiber by deep learning.Laser Photonics Rev.15, 2000553 (2021).. [Baidu Scholar]
Phan, T. et al. High-efficiency, large-area, topology-optimized metasurfaces.Light Sci. Appl.8, 48 (2019).. [Baidu Scholar]
Khorasaninejad, M. et al. Metalenses at visible wavelengths: diffraction-limited focusing and subwavelength resolution imaging.Science352, 1190–1194 (2016).. [Baidu Scholar]
Li, S. Q. et al. Phase-only transmissive spatial light modulator based on tunable dielectric metasurface.Science364, 1087–1090 (2019).. [Baidu Scholar]
Ren, H. R. et al. Complex-amplitude metasurface-based orbital angular momentum holography in momentum space.Nat. Nanotechnol.15, 948–955 (2020).. [Baidu Scholar]
Wang, S. et al. Metasurface-based solid poincaré sphere polarizer.Phys. Rev. Lett.130, 123801 (2023).. [Baidu Scholar]
Shen, Z. C. et al. Monocular metasurface camera for passive single-shot 4D imaging.Nat. Commun.14, 1035 (2023).. [Baidu Scholar]
Kim, G. et al. Metasurface-driven full-space structured light for three-dimensional imaging.Nat. Commun.13, 5920 (2022).. [Baidu Scholar]
Chu, H. C. et al. A hybrid invisibility cloak based on integration of transparent metasurfaces and zero-index materials.Light Sci. Appl.7, 50 (2018).. [Baidu Scholar]
Ren, H. R. et al. Metasurface orbital angular momentum holography.Nat. Commun.10, 2986 (2019).. [Baidu Scholar]
Zhang, S. F. et al. Full-Stokes polarization transformations and time sequence metasurface holographic display.Photonics Res.10, 1031–1038 (2022).. [Baidu Scholar]
Ouyang, X. et al. Synthetic helical dichroism for six-dimensional optical orbital angular momentum multiplexing.Nat. Photonics15, 901–907 (2021).. [Baidu Scholar]
Li, L. L. et al. Machine-learning reprogrammable metasurface imager.Nat. Commun.10, 1082 (2019).. [Baidu Scholar]
Liu, C. et al. A programmable diffractive deep neural network based on a digital-coding metasurface array.Nat. Electron.5, 113–122 (2022).. [Baidu Scholar]
Eliezer, Y. et al. Suppressing meta-holographic artifacts by laser coherence tuning.Light Sci. Appl.10, 104 (2021).. [Baidu Scholar]
Bender, N. et al. Circumventing the optical diffraction limit with customized speckles.Optica8, 122–129 (2021).. [Baidu Scholar]
Zhao, X. C. et al. Ultrahigh precision angular velocity measurement using frequency shift of partially coherent beams.Laser Photonics Rev.17, 2300318 (2023).. [Baidu Scholar]
Li, J. J. et al. Three-dimensional tomographic microscopy technique with multi-frequency combination with partially coherent illuminations.Biomed. Opt. Express9, 2526–2542 (2018).. [Baidu Scholar]
Peng, J. et al. Channel capacity of OAM based FSO communication systems with partially coherent Bessel–Gaussian beams in anisotropic turbulence.Opt. Commun.418, 32–36 (2018).. [Baidu Scholar]
Tan, Z. K. et al. Theoretical and experimental investigation on the performance of heterodyne detection system affected by the beam mode of partially coherent beams in atmospheric turbulence.Opt. Commun.466, 125638 (2020).. [Baidu Scholar]
Liu, L. X. et al. Spatial coherence manipulation on the disorder-engineered statistical photonic platform.Nano Lett.22, 6342–6349 (2022).. [Baidu Scholar]
Mandel, L.&Wolf, E.Optical Coherence and Quantum Optics(Cambridge University Press, 1995). [Baidu Scholar]
Hyde, I. V. et al. Generation of vector partially coherent optical sources using phase-only spatial light modulators.Phys. Rev. Appl.6, 064030 (2016).. [Baidu Scholar]
Chen, S. Q. et al. From single-dimensional to multidimensional manipulation of optical waves with metasurfaces.Adv. Mater.31, 1802458 (2019).. [Baidu Scholar]
Fan, Y. B., Yao, J.&Tsai, D. P. Advance of large-area achromatic flat lenses.Light Sci. Appl.12, 51 (2023).. [Baidu Scholar]
Liu, W. W. et al. Design strategies and applications of dimensional optical field manipulation based on metasurfaces.Adv. Mater.35, 2208884 (2023).. [Baidu Scholar]
Chen, Y. H. et al. Self-splitting properties of a Hermite-Gaussian correlated Schell-model beam.Phys. Rev. A91, 013823 (2015).. [Baidu Scholar]
Chen, Y. H. et al. Elliptical Laguerre-Gaussian correlated Schell-model beam.Opt. Express22, 13975–13987 (2014).. [Baidu Scholar]
Khorasaninejad, M.&Capasso, F. Metalenses: versatile multifunctional photonic components.Science358, eaam8100 (2017).. [Baidu Scholar]
Liu, W. W. et al. Aberration-corrected three-dimensional positioning with a single-shot metalens array.Optica7, 1706–1713 (2020).. [Baidu Scholar]
Xiong, J. H. et al. Perovskite single-pixel detector for dual-color metasurface imaging recognition in complex environment.Light Sci. Appl.12, 286 (2023).. [Baidu Scholar]
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