Nanoimprint lithography for high-throughput fabrication of metasurfaces

Abstract

Metasurfaces are composed of periodic subwavelength nanostructures and exhibit optical properties that are not found in nature. They have been widely investigated for optical applications such as holograms, wavefront shaping, and structural color printing, however, electron-beam lithography is not suitable to produce large-area metasurfaces because of the high fabrication cost and low productivity. Although alternative optical technologies, such as holographic lithography and plasmonic lithography, can overcome these drawbacks, such methods are still constrained by the optical diffraction limit. To break through this fundamental problem, mechanical nanopatterning processes have been actively studied in many fields, with nanoimprint lithography (NIL) coming to the forefront. Since NIL replicates the nanopattern of the mold regardless of the diffraction limit, NIL can achieve sufficiently high productivity and patterning resolution, giving rise to an explosive development in the fabrication of metasurfaces. In this review, we focus on various NIL technologies for the manufacturing of metasurfaces. First, we briefly describe conventional NIL and then present various NIL methods for the scalable fabrication of metasurfaces. We also discuss recent applications of NIL in the realization of metasurfaces. Finally, we conclude with an outlook on each method and suggest perspectives for future research on the high-throughput fabrication of active metasurfaces.

Graphical abstract

Keywords

nanoimprint / scalable fabrication / large-area metasurface / tailored nanostructure / hierarchical nano-structures

References

[1] Lemoult F, Kaina N, Fink M, Lerosey G. Wave propagation control at the deep subwavelength scale in metamaterials. Nature Physics, 2013, 9(11): 55–60

[2] Lee C W, Choi H J, Jeong H. Tunable metasurfaces for visible and SWIR applications. Nano Convergence, 2020, 7(1): 3

[3] Chen Y, Ai B, Wong Z J. Soft optical metamaterials. Nano Convergence, 2020, 7(1): 18

[4] Lawrence M, Barton D R 3rd, Dixon J, Song J H, van de Groep J, Brongersma M L, Dionne J A. High quality factor phase gradient metasurfaces. Nature Nanotechnology, 2020, 15(11): 956–961

[5] Yoon G, Lee D, Nam K T, Rho J. Geometric metasurface enabling polarization independent beam splitting. Scientific Reports, 2018, 8(1): 9468

[6] Wu P C, Pala R A, Kafaie Shirmanesh G, Cheng W H, Sokhoyan R, Grajower M, Alam M Z, Lee D, Atwater H A. Dynamic beam steering with all-dielectric electro-optic III-V multiple-quantum-well metasurfaces. Nature Communications, 2019, 10(1): 3654

[7] Wong Z J, Wang Y, O’Brien K, Rho J, Yin X B, Zhang S, Fang N, Yen T J, Zhang X. Optical and acoustic metamaterials: Superlens, negative refractive index and invisibility cloak. Journal of Optics, 2017, 19(8): 084007

[8] Bang S, So S, Rho J. Realization of broadband negative refraction in visible range using vertically stacked hyperbolic metamaterials. Scientific Reports, 2019, 9(1): 14093

[9] Yu N, Capasso F. Flat optics with designer metasurfaces. Nature Materials, 2014, 13(2): 139–150

[10] Lee D, Yang Y, Yoon G, Kim M, Rho J. Resolution enhancement of fluorescence microscopy using encoded patterns from all-dielectric metasurfaces. Applied Physics Letters, 2019, 115(10): 101102

[11] Lee D, Kim M, Kim J, Hong H, Badloe T, Kim D S, Rho J. All-dielectric metasurface imaging platform applicable to laser scanning microscopy with enhanced axial resolution and wavelength selection. Optical Materials Express, 2019, 9(8): 3248–3259

[12] Kim M, Rho J. Metamaterials and imaging. Nano Convergence, 2015, 2(1): 22

[13] Byun M, Lee D, Kim M, Kim Y, Kim K, Ok J G, Rho J, Lee H. Demonstration of nanoimprinted hyperlens array for high-throughput sub-diffraction imaging. Scientific Reports, 2017, 7(1): 46314

[14] Lee D, Kim Y D, Kim M, So S, Choi H J, Mun J, Nguyen D M, Badloe T, Ok J G, Kim K, Lee H, Rho J. Realization of wafer-scale hyperlens device for sub-diffractional biomolecular imaging. ACS Photonics, 2018, 5(7): 2549–2554

[15] Jang J, Badloe T, Yang Y, Lee T, Mun J, Rho J. Spectral modulation through the hybridization of Mie-scatterers and quasi-guided mode resonances: realizing full and gradients of structural color. ACS Nano, 2020, 14(11): 15317–15326

[16] Mudachathi R, Tanaka T. Up scalable full colour plasmonic pixels with controllable hue, brightness and saturation. Scientific Reports, 2017, 7(1): 1199

[17] Lee Y, Park M K, Kim S, Shin J H, Moon C, Hwang J Y, Choi J C, Park H, Kim H R, Jang J E. Electrical broad tuning of plasmonic color filter employing an asymmetric-lattice nanohole array of metasurface controlled by polarization rotator. ACS Photonics, 2017, 4(8): 1954–1966

[18] Lee D, Gwak J, Badloe T, Palomba S, Rho J. Metasurfaces-based imaging and applications: from miniaturized optical components to functional imaging platforms. Nanoscale Advances, 2020, 2(2): 605–625

[19] Lee T, Jang J, Jeong H, Rho J. Plasmonic- and dielectric-based structural coloring: from fundamentals to practical applications. Nano Convergence, 2018, 5(1): 1

[20] Kim M, Kim I, Jang J, Lee D, Nam K T, Rho J. Active color control in a metasurface by polarization rotation. Applied Sciences (Basel, Switzerland), 2018, 8(6): 982

[21] Yoon G, Lee D, Nam K T, Rho J. “Crypto-display” in dual-mode metasurfaces by simultaneous control of phase and spectral responses. ACS Nano, 2018, 12(7): 6421–6428

[22] Jang J, Kang K, Raeis-Hosseini N, Ismukhanova A, Jeong H, Jung C, Kim B, Lee J Y, Park I, Rho J. Self-powered humidity sensor using chitosan-based plasmonic metal-hydrogel-metal filters. Advanced Optical Materials, 2020, 8(9): 1901932

[23] Aoni R A, Rahmani M, Xu L, Zangeneh Kamali K, Komar A, Yan J, Neshev D, Miroshnichenko A E. High-efficiency visible light manipulation using dielectric metasurfaces. Scientific Reports, 2019, 9(1): 6510

[24] Jang J, Badloe T, Sim Y C, Yang Y, Mun J, Lee T, Cho Y H, Rho J. Full and gradient structural colouration by lattice amplified gallium nitride Mie-resonators. Nanoscale, 2020, 12(41): 21392–21400

[25] Kim I, Ansari M A, Mehmood M Q, Kim W S, Jang J, Zubair M, Kim Y K, Rho J. Stimuli-responsive dynamic metaholographic displays with designer liquid crystal modulators. Advanced Materials, 2020, 32(50): e2004664

[26] Kim I, Yoon G, Jang J, Genevet P, Nam K T, Rho J. Outfitting next generation displays with optical metasurfaces. ACS Photonics, 2018, 5(10): 3876–3895

[27] Li Z, Kim I, Zhang L, Mehmood M Q, Anwar M S, Saleem M, Lee D, Nam K T, Zhang S, Luk’yanchuk B, Wang Y, Zheng G, Rho J, Qiu C W. Dielectric meta-holograms enabled with dual magnetic resonances in visible light. ACS Nano, 2017, 11(9): 9382–9389

[28] Lee G Y, Yoon G, Lee S Y, Yun H, Cho J, Lee K, Kim H, Rho J, Lee B. Complete amplitude and phase control of light using broadband holographic metasurfaces. Nanoscale, 2018, 10(9): 4237–4245

[29] Ansari M A, Kim I, Lee D, Waseem M H, Zubair M, Mahmood N, Badloe T, Yerci S, Tauqeer T, Mehmood M Q, Rho J. A spin-encoded all-dielectric metahologram for visible light. Laser & Photonics Reviews, 2019, 13(5): 1900065

[30] Yoon G, Kim J, Mun J, Lee D, Nam K T, Rho J. Wavelength-decoupled geometric metasurfaces by arbitrary dispersion control. Communications on Physics, 2019, 2(1): 129

[31] Ansari M A, Kim I, Rukhlenko I D, Zubair M, Yerci S, Tauqeer T, Mehmood M Q, Rho J. Engineering spin and antiferromagnetic resonances to realize an efficient direction-multiplexed visible meta-hologram. Nanoscale Horizons, 2020, 5(1): 57–64

[32] Yoon G, Lee D, Nam K T, Rho J. Pragmatic metasurface hologram at visible wavelength: the balance between diffraction efficiency and fabrication compatibility. ACS Photonics, 2018, 5(5): 1643–1647

[33] Ren H, Fang X, Jang J, Bürger J, Rho J, Maier S A. Complex-amplitude metasurface-based orbital angular momentum holography in momentum space. Nature Nanotechnology, 2020, 15(11): 948–955

[34] Rana A S, Mehmood M Q, Jeong H, Kim I, Rho J. Tungsten-based ultrathin absorber for visible regime. Scientific Reports, 2018, 8(1): 2443

[35] Barho F B, Gonzalez-Posada F, Cerutti L, Taliercio T. Heavily doped semiconductor metamaterials for mid-infrared multispectral perfect absorption and thermal emission. Advanced Optical Materials, 2020, 8(6): 1901502

[36] Yoon G, So S, Kim M, Mun J, Ma R, Rho J. Electrically tunable metasurface perfect absorber for infrared frequencies. Nano Convergence, 2017, 4(1): 36

[37] Nguyen D M, Lee D, Rho J. Control of light absorbance using plasmonic grating based perfect absorber at visible and near-infrared wavelengths. Scientific Reports, 2017, 7(1): 2611

[38] Badloe T, Mun J, Rho J. Metasurfaces-based absorption and reflection control: perfect absorbers and reflectors. Journal of Nanomaterials, 2017, 2017(1): 2361042

[39] Badloe T, Kim I, Rho J. Moth-eye shaped on-demand broadband and switchable perfect absorbers based on vanadium dioxide. Scientific Reports, 2020, 10(1): 4522

[40] Badloe T, Kim I, Rho J. Biomimetic ultra-broadband perfect absorbers optimised with reinforcement learning. Physical Chemistry Chemical Physics, 2020, 22(4): 2337–2342

[41] Kim I, So S, Rana A S, Mehmood M Q, Rho J. Thermally robust ring-shaped chromium perfect absorber of visible light. Nanophotonics, 2018, 7(11): 1827–1833

[42] Sajedian I, Badloe T, Lee H, Rho J. Deep Q-network to produce polarization-independent perfect solar absorbers: a statistical report. Nano Convergence, 2020, 7(1): 26

[43] Yoon G, Jang J, Mun J, Nam K T, Rho J. Metasurface zone plate for light manipulation in vectorial regime. Communications on Physics, 2019, 2(1): 156

[44] Yin X, Ye Z, Rho J, Wang Y, Zhang X. Photonic spin Hall effect at metasurfaces. Science, 2013, 339(6126): 1405–1407

[45] Wang Y H, Jin R C, Li J Q, Zhong F, Liu H, Kim I, Jo Y, Rho J, Dong Z G. Photonic spin hall effect by the spin-orbit interaction in a metasurface with elliptical nano-structures. Applied Physics Letters, 2017, 110(10): 101908

[46] Wang Y H, Kim I, Jin R C, Jeong H, Li J Q, Dong Z G, Rho J. Experimental verification of asymmetric transmission in continuous omega-shaped metamaterials. RSC Advances, 2018, 8(67): 38556–38561

[47] Hong J, Kim S J, Kim I, Yun H, Mun S E, Rho J, Lee B. Plasmonic metasurface cavity for simultaneous enhancement of optical electric and magnetic fields in deep subwavelength volume. Optics Express, 2018, 26(10): 13340–13348

[48] Kim I, So S, Mun J, Lee K H, Lee J H, Lee T, Rho J. Optical characterizations and thermal analyses of HfO₂/SiO₂ multilayered diffraction gratings for high-power continuous wave laser. Journal of Physics: Photonics, 2020, 2(2): 025004

[49] Mahmood N, Kim I, Mehmood M Q, Jeong H, Akbar A, Lee D, Saleem M, Zubair M, Anwar M S, Tahir F A, Rho J. Polarisation insensitive multifunctional metasurfaces based on all-dielectric nanowaveguides. Nanoscale, 2018, 10(38): 18323–18330

[50] Mahmood N, Jeong H, Kim I, Mehmood M Q, Zubair M, Akbar A, Saleem M, Anwar M S, Tahir F A, Rho J. Twisted non-diffracting beams through all dielectric meta-axicons. Nanoscale, 2019, 11(43): 20571–20578

[51] Li Z, Dai Q, Mehmood M Q, Hu G, Yanchuk B L, Tao J, Hao C, Kim I, Jeong H, Zheng G, Yu S, Alù A, Rho J, Qiu C W. Full-space cloud of random points with a scrambling metasurface. Light, Science & Applications, 2018, 7(1): 63

[52] Yoon G, Lee D, Rho J. Demonstration of equal-intensity beam generation by dielectric metasurfaces. Journal of Visualized Experiments, 2019, 148(148): e59066

[53] Lee H E, Ahn H Y, Mun J, Lee Y Y, Kim M, Cho N H, Chang K, Kim W S, Rho J, Nam K T. Amino-acid- and peptide-directed synthesis of chiral plasmonic gold nanoparticles. Nature, 2018, 556(7701): 360–365

[54] Raeis-Hosseini N, Rho J. Dual-functional nanoscale devices using phase-change materials: a reconfigurable perfect absorber with nonvolatile resistance-change memory characteristics. Applied Sciences (Basel, Switzerland), 2019, 9(3): 564

[55] Raeis-Hosseini N, Rho J. Metasurfaces based on phase-change material as a reconfigurable platform for multifunctional devices. Materials (Basel), 2017, 10(9): 1046

[56] Yoon G, Kim I, So S, Mun J, Kim M, Rho J. Fabrication of three-dimensional suspended, interlayered and hierarchical nanostructures by accuracy-improved electron beam lithography overlay. Scientific Reports, 2017, 7(1): 6668

[57] Seo I C, Woo B H, An S C, Lee E, Jeong H Y, Lim Y, Jun Y C. Electron-beam-induced nanopatterning of J-aggregate thin films for excitonic and photonic response control. Advanced Optical Materials, 2018, 6(20): 1800583

[58] Jung C, Yang Y, Jang J, Badloe T, Lee T, Mun J, Moon S W, Rho J. Near-zero reflection of all-dielectric structural coloration enabling polarization-sensitive optical encryption with enhanced switchability. Nanophotonics, 2020, 10(2): 919–926

[59] Zhou J, Qian H, Chen C F, Zhao J, Li G, Wu Q, Luo H, Wen S, Liu Z. Optical edge detection based on high-efficiency dielectric metasurface. Proceedings of the National Academy of Sciences of the United States of America, 2019, 116(23): 11137–11140

[60] Jeon T, Kim D H, Park S G. Holographic fabrication of 3D nanostructures. Advanced Materials Interfaces, 2018, 5(18): 1800330

[61] Oh Y, Lim J W, Kim J G, Wang H, Kang B H, Park Y W, Kim H, Jang Y J, Kim J, Kim D H, Ju B K. Plasmonic periodic nanodot arrays via laser interference lithography for organic photovoltaic cells with >10% efficiency. ACS Nano, 2016, 10(11): 10143–10151

[62] Bagheri S, Strohfeldt N, Sterl F, Berrier A, Tittl A, Giessen H. Large-area low-cost plasmonic perfect absorber chemical sensor fabricated by laser interference lithography. ACS Sensors, 2016, 1(9): 1148–1154

[63] Do Y S. A highly reproducible fabrication process for large-area plasmonic filters for optical applications. IEEE Access: Practical Innovations, Open Solutions, 2018, 6(1): 68961–68967

[64] Song M, Li X, Pu M, Guo Y, Liu K, Yu H, Ma X, Luo X. Color display and encryption with a plasmonic polarizing metamirror. Nanophotonics, 2018, 7(1): 323–331

[65] Gan Z, Cai J, Liang C, Chen L, Min S, Cheng X, Cui D, Li W D. Patterning of high-aspect-ratio nanogratings using phase-locked two-beam fiber-optic interference lithography. Journal of Vacuum Science & Technology B, Microelectronics and Nanometer Structures, 2019, 37(6): 060601

[66] Liang G, Wang C, Zhao Z, Wang Y, Yao N, Gao P, Luo Y, Gao G, Zhao Q, Luo X. Squeezing bulk plasmon polaritons through hyperbolic metamaterials for large area deep subwavelength interference lithography. Advanced Optical Materials, 2015, 3(9): 1248–1256

[67] Liu H C, Kong W J, Zhu Q G, Zheng Y, Shen K S, Zhang J, Lu H. Plasmonic interference lithography by coupling the bulk plasmon polariton mode and the waveguide mode. Journal of Physics D, Applied Physics, 2020, 53(13): 135103

[68] Gao P, Pu M, Ma X, Li X, Guo Y, Wang C, Zhao Z, Luo X. Plasmonic lithography for the fabrication of surface nanostructures with a feature size down to 9 nm. Nanoscale, 2020, 12(4): 2415–2421

[69] Luo J, Zeng B, Wang C, Gao P, Liu K, Pu M, Jin J, Zhao Z, Li X, Yu H, Luo X. Fabrication of anisotropically arrayed nano-slots metasurfaces using reflective plasmonic lithography. Nanoscale, 2015, 7(44): 18805–18812

[70] Wang C, Zhang W, Zhao Z, Wang Y, Gao P, Luo Y, Luo X. Plasmonic structures, materials and lenses for optical lithography beyond the diffraction limit: A review. Micromachines, 2016, 7(7): 118

[71] Kim S K. Impact of plasmonic parameters on 7-nm patterning in plasmonic computational lithography. Journal of Nanoscience and Nanotechnology, 2018, 18(10): 7124–7127

[72] Hong F, Blaikie R. Plasmonic lithography: recent progress. Advanced Optical Materials, 2019, 7(14): 1801653

[73] Kim I, Mun J, Baek K M, Kim M, Hao C, Qiu C W, Jung Y S, Rho J. Cascade domino lithography for extreme photon squeezing. Materials Today, 2020, 39(1): 89–97

[74] Kim I, Mun J, Hwang W, Yang Y, Rho J. Capillary-force-induced collapse lithography for controlled plasmonic nanogap structures. Microsystems & Nanoengineering, 2020, 6(1): 65

[75] Nam V B, Giang T T, Koo S, Rho J, Lee D. Laser digital patterning of conductive electrodes using metal oxide nanomaterials. Nano Convergence, 2020, 7(1): 23

[76] Chou S Y, Krauss P R, Renstrom P J. Nanoimprint lithography. Journal of Vacuum Science & Technology B, Microelectronics and Nanometer Structures: Processing, Measurement, and Phenomena, 1996, 14(6): 4129–4133

[77] Chou S Y, Krauss P R, Renstrom P J. Imprint lithography with 25-nanometer resolution. Science, 1996, 272(5258): 85–87

[78] Chou S Y. Sub-10 nm imprint lithography and applications. Journal of Vacuum Science & Technology B, Microelectronics and Nanometer Structures: Processing, Measurement, and Phenomena, 1997, 15(6): 2897–2904

[79] Haisma J, Verheijen M, van den Heuvel K, van den Berg J. Mold-assisted nanolithography: a process for reliable pattern replication. Journal of Vacuum Science & Technology B, Microelectronics and Nanometer Structures: Processing, Measurement, and Phenomena, 1996, 14(6): 4124–4128

[80] Austin M D, Ge H, Wu W, Li M, Yu Z, Wasserman D, Lyon S A, Chou S Y. Fabrication of 5 nm linewidth and 14 nm pitch features by nanoimprint lithography. Applied Physics Letters, 2004, 84(26): 5299–5301

[81] Plachetka U, Bender M, Fuchs A, Vratzov B, Glinsner T, Lindner F, Kurz H. Wafer scale patterning by soft UV-nanoimprint lithography. Microelectronic Engineering, 2004, 73–74(1): 167–171

[82] Sreenivasan S V. Nanoimprint lithography steppers for volume fabrication of leading-edge semiconductor integrated circuits. Microsystems & Nanoengineering, 2017, 3(1): 17075

[83] Qiao W, Huang W, Liu Y, Li X, Chen L S, Tang J X. Toward scalable flexible nanomanufacturing for photonic structures and devices. Advanced Materials, 2016, 28(47): 10353–10380

[84] Traub M C, Longsine W, Truskett V N. Advances in nanoimprint lithography. Annual Review of Chemical and Biomolecular Engineering, 2016, 7(1): 583–604

[85] Kim M, Lee D, Kim T H, Yang Y, Park H J, Rho J. Observation of enhanced optical spin hall effect in a vertical hyperbolic metamaterial. ACS Photonics, 2019, 6(10): 2530–2536

[86] Atighilorestani M, Jiang H, Kaminska B. Electrochromic-polymer-based switchable plasmonic color devices using surface-relief nanostructure pixels. Advanced Optical Materials, 2018, 6(23): 1801179

[87] Lee D, Han S Y, Jeong Y, Nguyen D M, Yoon G, Mun J, Chae J, Lee J H, Ok J G, Jung G Y, Park H J, Kim K, Rho J. Polarization-sensitive tunable absorber in visible and near-infrared regimes. Scientific Reports, 2018, 8(1): 12393

[88] Zhang H, Kinnear C, Mulvaney P. Fabrication of single-nanocrystal arrays. Advanced Materials, 2020, 32(18): e1904551

[89] Yoon G, Kim I, Rho J. Challenges in fabrication towards realization of practical metamaterials. Microelectronic Engineering, 2016, 163(1): 7–20

[90] Yao Y, Liu H, Wang Y, Li Y, Song B, Wang R P, Povinelli M L, Wu W. Nanoimprint-defined, large-area meta-surfaces for unidirectional optical transmission with superior extinction in the visible-to-infrared range. Optics Express, 2016, 24(14): 15362–15372

[91] Lee G Y, Hong J Y, Hwang S, Moon S, Kang H, Jeon S, Kim H, Jeong J H, Lee B. Metasurface eyepiece for augmented reality. Nature Communications, 2018, 9(1): 4562

[92] Wan Y H, Krueger N A, Ocier C R, Su P, Braun P V, Cunningham B T. Resonant mode engineering of photonic crystal sensors clad with ultralow refractive index porous silicon dioxide. Advanced Optical Materials, 2017, 5(21): 1700605

[93] Sutherland B R, Sargent E H. Perovskite photonic sources. Nature Photonics, 2016, 10(5): 295–302

[94] Chun D H, Choi Y J, In Y, Nam J K, Choi Y J, Yun S, Kim W, Choi D, Kim D, Shin H, Cho J H, Park J H. Halide perovskite nanopillar photodetector. ACS Nano, 2018, 12(8): 8564–8571

[95] Pourdavoud N, Wang S, Mayer A, Hu T, Chen Y, Marianovich A, Kowalsky W, Heiderhoff R, Scheer H C, Riedl T. Photonic nanostructures patterned by thermal nanoimprint directly into organo-metal halide perovskites. Advanced Materials, 2017, 29(12): 1605003

[96] Mao J, Sha W E I, Zhang H, Ren X G, Zhuang J Q, Roy V A L, Wong K S, Choy W C H. Novel direct nanopatterning approach to fabricate periodically nanostructured perovskite for optoelectronic applications. Advanced Functional Materials, 2017, 27(10): 1606525

[97] Makarov S V, Milichko V, Ushakova E V, Omelyanovich M, Pasaran A C, Haroldson R, Balachandran B, Wang H L, Hu W, Kivshar Y S, Zakhidov A A. Multifold emission enhancement in nanoimprinted hybrid perovskite metasurfaces. ACS Photonics, 2017, 4(4): 728–735

[98] Wang H, Liu S C, Balachandran B, Moon J, Haroldson R, Li Z, Ishteev A, Gu Q, Zhou W, Zakhidov A, Hu W. Nanoimprinted perovskite metasurface for enhanced photoluminescence. Optics Express, 2017, 25(24): A1162–A1171

[99] Baek S W, Molet P, Choi M J, Biondi M, Ouellette O, Fan J, Hoogland S, García de Arquer F P, Mihi A, Sargent E H. Nanostructured back reflectors for efficient colloidal quantum-dot infrared optoelectronics. Advanced Materials, 2019, 31(33): e1901745

[100] Kim Y, Bicanic K, Tan H, Ouellette O, Sutherland B R, García de Arquer F P, Jo J W, Liu M, Sun B, Liu M, Hoogland S, Sargent E H. Nanoimprint-transfer-patterned solids enhance light absorption in colloidal quantum dot solar cells. Nano Letters, 2017, 17(4): 2349–2353

[101] Pina-Hernandez C, Koshelev A, Dhuey S, Sassolini S, Sainato M, Cabrini S, Munechika K. Nanoimprinted high-refractive index active photonic nanostructures based on quantum dots for visible light. Scientific Reports, 2017, 7(1): 17645

[102] Guo L J. Nanoimprint lithography: methods and material requirements. Advanced Materials, 2007, 19(4): 495–513

[103] Wang C, Shao J, Tian H, Li X, Ding Y, Li B Q. Step-controllable electric-field-assisted nanoimprint lithography for uneven large-area substrates. ACS Nano, 2016, 10(4): 4354–4363

[104] Ahn S H, Guo L J. High-speed roll-to-roll nanoimprint lithography on flexible plastic substrates. Advanced Materials, 2008, 20(11): 2044–2049

[105] Lee S H, Kim S W, Kang B S, Chang P S, Kwak M K. Scalable and continuous fabrication of bio-inspired dry adhesives with a thermosetting polymer. Soft Matter, 2018, 14(14): 2586–2593

[106] Wong H C, Grenci G, Wu J, Viasnoff V, Low H Y. Roll-to-roll fabrication of residual-layer-free micro/nanoscale membranes with precise pore architectures and tunable surface textures. Industrial & Engineering Chemistry Research, 2018, 57(41): 13759–13768

[107] Wang Z Z, Yi P Y, Peng L F, Lai X M, Ni J. Continuous fabrication of highly conductive and transparent Ag mesh electrodes for flexible electronics. IEEE Transactions on Nanotechnology, 2017, 16(4): 687–694

[108] Yi P Y, Zhang C P, Peng L F, Lai X M. Flexible silver-mesh electrodes with moth-eye nanostructures for transmittance enhancement by double-sided roll-to-roll nanoimprint lithography. RSC Advances, 2017, 7(77): 48835–48840

[109] Lee N, Yoo S, Kim C H, Lim J. Development of continuous metal patterns using two-dimensional atmospheric-pressure plasma-jet: On application to fabricate electrode on a flexible surface for film touch sensor. Journal of Micromechanics and Microengineering, 2019, 29(4): 045013

[110] Wang L J, Zheng Y S, Wu C, Jia S L. Experimental investigation of photoresist etching by kHz AC atmospheric pressure plasma jet. Applied Surface Science, 2016, 385(1): 191–198

[111] Zhou Y Q, Li M J, Shen L G, Ye H C, Wang J P, Huang S Z. Effect of resin accumulation on filling process in roll-to-roll UV imprint lithography. Journal of Vacuum Science & Technology B, Microelectronics and Nanometer Structures, 2017, 35(3): 031602

[112] Tahir U, Kamran M A, Jeong M Y. Numerical study on the optimization of roll-to-roll ultraviolet imprint lithography. Coatings, 2019, 9(9): 573

[113] Kotz F, Schneider N, Striegel A, Wolfschläger A, Keller N, Worgull M, Bauer W, Schild D, Milich M, Greiner C, Helmer D, Rapp B E. Glassomer-processing fused silica glass like a polymer. Advanced Materials, 2018, 30(22): e1707100

[114] Leitgeb M, Nees D, Ruttloff S, Palfinger U, Götz J, Liska R, Belegratis M R, Stadlober B. Multilength scale patterning of functional layers by roll-to-roll ultraviolet-light-assisted nanoimprint lithography. ACS Nano, 2016, 10(5): 4926–4941

[115] Koo S, Lee S H, Kim J D, Hong J G, Baac H W, Kwak M K, Ok J G. Controlled airbrush coating of polymer resists in roll-to-roll nanoimprinting with regimented residual layer thickness. International Journal of Precision Engineering and Manufacturing, 2016, 17(7): 943–947

[116] Lee J H, Na M, Kim J, Yoo K, Park J, Kim J D, Oh D K, Lee S, Youn H, Kwak M K, Ok J G. Rapid and conformal coating of polymer resins by airbrushing for continuous and high-speed roll-to-roll nanopatterning: parametric quality controls and extended applications. Nano Convergence, 2017, 4(1): 11

[117] Kodihalli Shivaprakash N, Ferraguto T, Panwar A, Banerjee S S, Barry C F, Mead J. Fabrication of flexible polymer molds for polymer microstructuring by roll-to-roll hot embossing. ACS Omega, 2019, 4(7): 12480–12488

[118] Striegel A, Schneider M, Schneider N, Benkel C, Worgull M. Seamless tool fabrication for roll-to-roll microreplication. Microelectronic Engineering, 2018, 194(1): 8–14

[119] Zhang X Q, Huang R, Liu K, Kumar A S, Shan X C. Rotating-tool diamond turning of Fresnel lenses on a roller mold for manufacturing of functional optical film. Precision Engineering, 2018, 51(1): 445–457

[120] Lee Y H, Ke K C, Chang N W, Yang S Y. Development of an UV rolling system for fabrication of micro/nano structure on polymeric films using a gas-roller-sustained seamless PDMS mold. Microsystem Technologies, 2018, 24(7): 2941–2948

[121] Lee C R, Ok J G, Jeong M Y. Nanopatterning on the cylindrical surface using an e-beam pre-mapping algorithm. Journal of Micromechanics and Microengineering, 2019, 29(1): 015004

[122] Dumond J J, Low H Y, Lee H P, Fuh J Y H. Multi-functional silicone stamps for reactive release agent transfer in UV roll-to-roll nanoimprinting. Materials Horizons, 2016, 3(2): 152–160

[123] Odom T W, Love J C, Wolfe D B, Paul K E, Whitesides G M. Improved pattern transfer in soft lithography using composite stamps. Langmuir, 2002, 18(13): 5314–5320

[124] Kim S, Hyun S, Lee J, Lee K S, Lee W, Kim J K. Anodized aluminum oxide/polydimethylsiloxane hybrid mold for roll-to-roll nanoimprinting. Advanced Functional Materials, 2018, 28(23): 1800197

[125] Ansari K, Kan J, Bettiol A A, Watt F. Stamps for nanoimprint lithography fabricated by proton beam writing and nickel electroplating. Journal of Micromechanics and Microengineering, 2006, 16(10): 1967–1974

[126] Liu F, Tan K B, Malar P, Bikkarolla S K, van Kan J A. Fabrication of nickel molds using proton beam writing for micro/nano fluidic devices. Microelectronic Engineering, 2013, 102(1): 36–39

[127] Lin X, Dou X, Wang X, Chen R T. Nickel electroplating for nanostructure mold fabrication. Journal of Nanoscience and Nanotechnology, 2011, 11(8): 7006–7010

[128] Kwak M K, Ok J G, Lee S H, Guo L J. Visually tolerable tiling (VTT) for making a large-area flexible patterned surface. Materials Horizons, 2015, 2(1): 86–90

[129] Ok J G, Ahn S H, Kwak M K, Guo L J. Continuous and high-throughput nanopatterning methodologies based on mechanical deformation. Journal of Materials Chemistry C, Materials for Optical and Electronic Devices, 2013, 1(46): 7681–7691

[130] Ok J G, Shin Y J, Park H J, Guo L J. A step toward next-generation nanoimprint lithography: extending productivity and applicability. Applied Physics A, Materials Science & Processing, 2015, 121(2): 343–356

[131] Ok J G, Park H J, Kwak M K, Pina-Hernandez C A, Ahn S H, Guo L J. Continuous patterning of nanogratings by nanochannel-guided lithography on liquid resists. Advanced Materials, 2011, 23(38): 4444–4448

[132] Ahn S H, Guo L J. Dynamic nanoinscribing for continuous and seamless metal and polymer nanogratings. Nano Letters, 2009, 9(12): 4392–4397

[133] Oh D K, Nguyen D T, Lee S, Ko P, Heo G S, Yun C H, Ha T W, Youn H, Ok J G. Facile and scalable fabrication of flexible reattachable ionomer nanopatterns by continuous multidimensional nanoinscribing and low-temperature roll imprinting. ACS Applied Materials & Interfaces, 2019, 11(12): 12070–12076

[134] Oh D K, Lee S, Lee S H, Lee W, Yeon G, Lee N, Han K S, Jung S, Kim D H, Lee D Y, Lee S H, Park H J, Ok J G. Tailored nanopatterning by controlled continuous nanoinscribing with tunable shape, depth, and dimension. ACS Nano, 2019, 13(10): 11194–11202

[135] Ahn S H, Ok J G, Kwak M K, Lee K T, Lee J Y, Guo L J. Template-free vibrational indentation patterning (VIP) of micro/nanometer-scale grating structures with real-time pitch and angle tunability. Advanced Functional Materials, 2013, 23(37): 4739–4744

[136] Ok J G, Panday A, Lee T, Jay Guo L. Continuous fabrication of scalable 2-dimensional (2D) micro- and nanostructures by sequential 1D mechanical patterning processes. Nanoscale, 2014, 6(24): 14636–14642

[137] Ahiboz D, Manley P, Becker C. Adjustable large-area dielectric metasurfaces for near-normal oblique incident excitation. OSA Continuum, 2020, 3(4): 971–981

[138] Zhu J, Wang Z, Lin S, Jiang S, Liu X, Guo S. Low-cost flexible plasmonic nanobump metasurfaces for label-free sensing of serum tumor marker. Biosensors & Bioelectronics, 2020, 150(1): 111905

[139] Das Gupta T, Martin-Monier L, Yan W, Le Bris A, Nguyen-Dang T, Page A G, Ho K T, Yesilköy F, Altug H, Qu Y, Sorin F. Self-assembly of nanostructured glass metasurfaces via templated fluid instabilities. Nature Nanotechnology, 2019, 14(4): 320–327

[140] Shneidman A V, Becker K P, Lukas M A, Torgerson N, Wang C, Reshef O, Burek M J, Paul K, McLellan J, Lončar M. All-polymer integrated optical resonators by roll-to-roll nanoimprint lithography. ACS Photonics, 2018, 5(5): 1839–1845

[141] Zhang C, Yi P, Peng L, Lai X, Chen J, Huang M, Ni J. Continuous fabrication of nanostructure arrays for flexible surface enhanced Raman scattering substrate. Scientific Reports, 2017, 7(1): 39814

[142] Suresh V, Ding L, Chew A B, Yap F L. Fabrication of large-area flexible SERS substrates by nanoimprint lithography. ACS Applied Nano Materials, 2018, 1(2): 886–893

[143] Deng Y, Yi P, Peng L, Lai X, Lin Z. Experimental investigation on the large-area fabrication of micro-pyramid arrays by roll-to-roll hot embossing on PVC film. Journal of Micromechanics and Microengineering, 2014, 24(4): 045023

[144] Højlund-Nielsen E, Clausen J, Mäkela T, Thamdrup L H, Zalkovskij M, Nielsen T, Li Pira N, Ahopelto J, Mortensen N A, Kristensen A. Plasmonic colors: toward mass production of metasurfaces. Advanced Materials Technologies, 2016, 1(7): 1600054

[145] Murthy S, Pranov H, Feidenhans’l N A, Madsen J S, Hansen P E, Pedersen H C, Taboryski R. Plasmonic color metasurfaces fabricated by a high speed roll-to-roll method. Nanoscale, 2017, 9(37): 14280–14287

[146] Ok J G, Youn H S, Kwak M K, Lee K T, Shin Y J, Guo L J, Greenwald A, Liu Y S. Continuous and scalable fabrication of flexible metamaterial films via roll-to-roll nanoimprint process for broadband plasmonic infrared filters. Applied Physics Letters, 2012, 101(22): 223102

[147] Wi J S, Lee S, Lee S H, Oh D K, Lee K T, Park I, Kwak M K, Ok J G. Facile three-dimensional nanoarchitecturing of double-bent gold strips on roll-to-roll nanoimprinted transparent nanogratings for flexible and scalable plasmonic sensors. Nanoscale, 2017, 9(4): 1398–1402

[148] Wi J S, Oh D K, Kwak M K, Ok J G. Size-dependent detection sensitivity of spherical particles sitting on a double-bent gold strip array. Optical Materials Express, 2018, 8(7): 1774–1779

[149] Jeon S, Shir D J, Nam Y S, Nidetz R, Highland M, Cahill D G, Rogers J A, Su M F, El-Kady I F, Christodoulou C G, Bogart G R. Molded transparent photopolymers and phase shift optics for fabricating three dimensional nanostructures. Optics Express, 2007, 15(10): 6358–6366

[150] Choi J H, Oh C M, Jang J W. Micro- and nano-patterns fabricated by embossed microscale stamp with trenched edges. RSC Advances, 2017, 7(51): 32058–32064

[151] Yanagishita T, Murakoshi K, Kondo T, Masuda H. Preparation of superhydrophobic surfaces with micro/nano alumina molds. RSC Advances, 2018, 8(64): 36697–36704

[152] Kim S J, Jung P H, Kim W, Lee H, Hong S H. Generation of highly integrated multiple vivid colours using a three-dimensional broadband perfect absorber. Scientific Reports, 2019, 9(1): 14859

[153] Jeong H E, Lee J K, Kim H N, Moon S H, Suh K Y. A nontransferring dry adhesive with hierarchical polymer nanohairs. Proceedings of the National Academy of Sciences of the United States of America, 2009, 106(14): 5639–5644

[154] Karageorgiev P, Neher D, Schulz B, Stiller B, Pietsch U, Giersig M, Brehmer L. From anisotropic photo-fluidity towards nanomanipulation in the optical near-field. Nature Materials, 2005, 4(9): 699–703

[155] Choi J, Cho W, Jung Y S, Kang H S, Kim H T. Direct fabrication of micro/nano-patterned surfaces by vertical-directional photofluidization of azobenzene materials. ACS Nano, 2017, 11(2): 1320–1327

[156] Choi J, Jo W, Lee S Y, Jung Y S, Kim S H, Kim H T. Flexible and robust superomniphobic surfaces created by localized photofluidization of azopolymer pillars. ACS Nano, 2017, 11(8): 7821–7828

[157] Liu Z, Cui Q, Huang Z, Guo L J. Transparent colored display enabled by flat glass waveguide and nanoimprinted multilayer gratings. ACS Photonics, 2020, 7(6): 1418–1424

[158] Kothari R, Beaulieu M R, Hendricks N R, Li S, Watkins J J. Direct patterning of robust one-dimensional, two-dimensional, and three-dimensional crystalline metal oxide nanostructures using imprint lithography and nanoparticle dispersion inks. Chemistry of Materials, 2017, 29(9): 3908–3918

[159] Li W, Zhou Y, Howell I R, Gai Y, Naik A R, Li S, Carter K R, Watkins J J. Direct imprinting of scalable, high-performance woodpile electrodes for three-dimensional lithium-ion nanobatteries. ACS Applied Materials & Interfaces, 2018, 10(6): 5447–5454

[160] Liu D M, Wang Q K, Wang Q. Transfer the multiscale texture of crystalline Si onto thin-film micromorph cell by UV nanoimprint for light trapping. Applied Surface Science, 2018, 439(1): 168–175

[161] Choi J, Jia Z, Park S. Fabrication of polymeric dual-scale nanoimprint molds using a polymer stencil membrane. Microelectronic Engineering, 2018, 199(1): 101–105

[162] Han K S, Hong S H, Kim K I, Cho J Y, Choi K W, Lee H. Fabrication of 3D nano-structures using reverse imprint lithography. Nanotechnology, 2013, 24(4): 045304

[163] Kwon Y W, Park J, Kim T, Kang S H, Kim H, Shin J, Jeon S, Hong S W. Flexible near-field nanopatterning with ultrathin, conformal phase masks on nonplanar substrates for biomimetic hierarchical photonic structures. ACS Nano, 2016, 10(4): 4609–4617

[164] Wang C, Shao J, Lai D, Tian H, Li X. Suspended-template electric-assisted nanoimprinting for hierarchical micro-nanostructures on a fragile substrate. ACS Nano, 2019, 13(9): 10333–10342

[165] Chandramohan A, Sibirev N V, Dubrovskii V G, Petty M C, Gallant A J, Zeze D A. Model for large-area monolayer coverage of polystyrene nanospheres by spin coating. Scientific Reports, 2017, 7(1): 40888

[166] Nakagawa M, Nakaya A, Hoshikawa Y, Ito S, Hiroshiba N, Kyotani T. Size-dependent filling behavior of UV-curable di(meth)acrylate resins into carbon-coated anodic aluminum oxide pores of around 20 nm. ACS Applied Materials & Interfaces, 2016, 8(44): 30628–30634

[167] Hua F, Sun Y G, Gaur A, Meitl M A, Bilhaut L, Rotkina L, Wang J F, Geil P, Shim M, Rogers J A, Shim A. Polymer imprint lithography with molecular-scale resolution. Nano Letters, 2004, 4(12): 2467–2471

[168] Yim W, Park S J, Han S Y, Park Y H, Lee S W, Park H J, Ahn Y H, Lee S, Park J Y. Carbon nanotubes as etching masks for the formation of polymer nanostructures. ACS Applied Materials & Interfaces, 2017, 9(50): 44053–44059

[169] Pi S, Lin P, Xia Q. Fabrication of sub-10 nm metal nanowire arrays with sub-1 nm critical dimension control. Nanotechnology, 2016, 27(46): 464004

[170] Woo J Y, Jo S, Oh J H, Kim J T, Han C S. Facile and precise fabrication of 10-nm nanostructures on soft and hard substrates. Applied Surface Science, 2019, 484(1): 317–325

[171] Lim S H, Saifullah M S, Hussain H, Loh W W, Low H Y. Direct imprinting of high resolution TiO₂ nanostructures. Nanotechnology, 2010, 21(28): 285303

[172] Menumerov E, Golze S D, Hughes R A, Neretina S. Arrays of highly complex noble metal nanostructures using nanoimprint lithography in combination with liquid-phase epitaxy. Nanoscale, 2018, 10(38): 18186–18194

[173] Pina-Hernandez C, Fu P F, Guo L J. Ultrasmall structure fabrication via a facile size modification of nanoimprinted functional silsesquioxane features. ACS Nano, 2011, 5(2): 923–931

[174] Yao Y H, Wang Y F, Liu H, Li Y R, Song B X, Wu W. Line width tuning and smoothening for periodical grating fabrication in nanoimprint lithography. Applied Physics A, Materials Science & Processing, 2015, 121(2): 399–403

[175] Wang S S, Magnusson R. Theory and applications of guided-mode resonance filters. Applied Optics, 1993, 32(14): 2606–2613

[176] Liu Z. One-step fabrication of crystalline metal nanostructures by direct nanoimprinting below melting temperatures. Nature Communications, 2017, 8(1): 14910

[177] Bhadauriya S, Wang X, Pitliya P, Zhang J, Raghavan D, Bockstaller M R, Stafford C M, Douglas J F, Karim A. Tuning the relaxation of nanopatterned polymer films with polymer-grafted nanoparticles: observation of entropy-enthalpy compensation. Nano Letters, 2018, 18(12): 7441–7447

[178] Liu L, Zhang Q, Lu Y S, Du W, Li B, Cui Y S, Yuan C S, Zhan P, Ge H X, Wang Z L, Chen Y F. A high-performance and low cost SERS substrate of plasmonic nanopillars on plastic film fabricated by nanoimprint lithography with AAO template. AIP Advances, 2017, 7(6): 065205

[179] Jung Y, Hwang I, Yu J, Lee J, Choi J H, Jeong J H, Jung J Y, Lee J. Fano metamaterials on nanopedestals for plasmon-enhanced infrared spectroscopy. Scientific Reports, 2019, 9(1): 7834

[180] Yao Y H, Wu W. All-dielectric heterogeneous metasurface as an efficient ultra-broadband reflector. Advanced Optical Materials, 2017, 5(14): 1700090

[181] Hemmati H, Magnusson R. Resonant dual-grating metamembranes supporting spectrally narrow bound states in the continuum. Advanced Optical Materials, 2019, 7(20): 1900754

[182] Zhang C, Subbaraman H, Li Q, Pan Z, Ok J G, Ling T, Chung C J, Zhang X, Lin X, Chen R T, Guo L J. Printed photonic elements: nanoimprinting and beyond. Journal of Materials Chemistry C, Materials for Optical and Electronic Devices, 2016, 4(23): 5133–5153

[183] Lee K T, Jang J Y, Park S J, Ji C G, Yang S M, Guo L J, Park H J. Angle-insensitive and CMOS-compatible subwavelength color printing. Advanced Optical Materials, 2016, 4(11): 1696–1702

[184] Liu H, Yang H, Li Y R, Song B X, Wang Y F, Liu Z R, Peng L, Lim H, Yoon J, Wu W. Switchable all-dielectric metasurfaces for full-color reflective display. Advanced Optical Materials, 2019, 7(8): 1801639

[185] Joo W J, Kyoung J, Esfandyarpour M, Lee S H, Koo H, Song S, Kwon Y N, Song S H, Bae J C, Jo A, Kwon M J, Han S H, Kim S H, Hwang S, Brongersma M L. Metasurface-driven OLED displays beyond 10000 pixels per inch. Science, 2020, 370(6515): 459–463

[186] Yoon G, Kim K, Kim S U, Han S, Lee H, Rho J. Printable nanocomposite metalens for high-contrast near-infrared imaging. ACS Nano, 2021, 15(1): 698–706

[187] Checcucci S, Bottein T, Gurioli M, Favre L, Grosso D, Abbarchi M. Multifunctional metasurfaces based on direct nanoimprint of titania sol-gel coatings. Advanced Optical Materials, 2019, 7(10): 1801406

[188] Kim K, Yoon G, Baek S, Rho J, Lee H. Facile nanocasting of dielectric metasurfaces with sub-100 nm resolution. ACS Applied Materials & Interfaces, 2019, 11(29): 26109–26115

[189] Yoon G, Kim K, Huh D, Lee H, Rho J. Single-step manufacturing of hierarchical dielectric metalens in the visible. Nature Communications, 2020, 11(1): 2268

[190] Gopalan K K, Paulillo B, Mackenzie D M A, Rodrigo D, Bareza N, Whelan P R, Shivayogimath A, Pruneri V. Scalable and tunable periodic graphene nanohole arrays for mid-infrared plasmonics. Nano Letters, 2018, 18(9): 5913–5918

[191] Zhao Z J, Lee M, Kang H, Hwang S, Jeon S, Park N, Park S H, Jeong J H. Eight inch wafer-scale flexible polarization-dependent color filters with Ag-TiO₂ composite nanowires. ACS Applied Materials & Interfaces, 2018, 10(10): 9188–9196

[192] Driencourt L, Federspiel F, Kazazis D, Tseng L T, Frantz R, Ekinci Y, Ferrini R, Gallinet B. Electrically tunable multicolored filter using birefringent plasmonic resonators and liquid crystals. ACS Photonics, 2020, 7(2): 444–453

[193] Shin Y J, Pina-Hernandez C, Wu Y K, Ok J G, Guo L J. Facile route of flexible wire grid polarizer fabrication by angled-evaporations of aluminum on two sidewalls of an imprinted nanograting. Nanotechnology, 2012, 23(34): 344018

[194] Matricardi C, Garcia-Pomar J L, Molet P, Perez L A, Alonso M I, Campoy-Quiles M, Mihi A. High-throughput nanofabrication of metasurfaces with polarization-dependent response. Advanced Optical Materials, 2020, 8(20): 2000786

[195] Yoon G, Kim K, Kim S U, Han S, Lee H, Rho J. Printable nanocomposite metalens for high-contrast near-infrared imaging. ACS Nano, 2021, 15(1): 698–706

[196] Yang Y, Yoon G, Park S, Namgung S D, Badloe T, Nam K T, Rho J. Revealing structural disorder in hydrogenated amorphous silicon for a low-loss photonic platform at visible frequencies. Advanced Materials, 2021, 33(9): e2005893

[197] Oh D K, Jeong H, Kim J, Kim Y, Kim I, Ok J G, Rho J. Top-down nanofabrication approaches toward single-digit-nanometer scale structures. Journal of Mechanical Science and Technology, 20201, 35(3): 837–859

[198] Stolt T, Kim J, Héron S, Vesala A, Yang Y, Mun J, Kim M, Huttunen M J, Czaplicki R, Kauranen M, Rho J, Genevet P. Backward phase-matched second-harmonic generation from stacked metasurfaces. Physical Review Letters, 2021, 126(3): 033901

[199] Lee D, Go M, Kim M, Jang J, Choi C, Kim J K, Rho J. Multiple-patterning colloidal lithography-implemented scalable manufacturing of heat-tolerant titanium nitride broadband absorbers in the visible to near-infrared. Microsystems & Nanoengineering, 2021, 7(1): 14

[200] Kim I, Ansari M A, Mehmood M Q, Kim W S, Jang J, Zubair M, Kim Y K, Rho J. Stimuli-responsive dynamic metaholographic displays with designer liquid crystal modulators. Advanced Materials, 2020, 32(50): e2004664

[201] Chen Y, Ai B, Wong Z J. Soft optical metamaterials. Nano Convergence, 2020, 7(1): 18

[202] Naveed M A, Ansari M A, Kim I, Badloe T, Kim J, Oh D K, Riaz K, Tauqeer T, Younis U, Saleem M, Anwar M S, Zubair M, Mehmood M Q, Rho J. Optical spin-symmetry breaking for high-efficiency directional helicity-multiplexed metaholograms. Microsystems & Nanoengineering, 2021, 7(1): 5

Acknowledgements

This work was financially supported by the National Research Foundation (NRF) grant (NRF-2019R1A2C3003129) funded by the Ministry of Science and ICT, Republic of Korea. T.L. acknowledges the NRF Global Ph.D. fellowship (NRF-2019H1A2A1076295) funded by the Ministry of Education, Republic of Korea.

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