• Special Issue
  • Advances in Metasurfaces
  • 9 Article (s)
Editorial for special issue on advances in metasurfaces
Qiwen Zhan, and Qiaoqiang Gan
Metasurface refers to a type of artificial thin film materials with sub-wavelength features that can generate the desired and/or new optical phenomena. The past decade has witnessed significant advances in the metasurface, ranging from fundamental physics to nanomanufacturing methods and practical applications. Typical research efforts include wave-front engineering and detection [e.g., Yu, Science 334, 333 (2011); Capasso, Nat. Commun. 3, 1278 (2012)], flat optics for focusing and imaging [e.g., Cappaso, Nano Lett. 12, 4932 (2012); Yu, Nat. Mater. 13, 139 (2014)], polarization manipulation [e.g., Zhan, Opt. Lett. 40, 4711 (2015); Sci. Rep. 6, 29626 (2016)], metahologram [e.g., Genevet, Rep. Prog. Phys. 78, 24401 (2015); Tsai, Nano Lett. 14, 225 (2014)], light trapping and localization [e.g., Gan, Adv. Mater. 26, 2737 (2014); Adv. Opt. Mater. 5, 1700223 (2017)], absorption engineering [Gan, Adv. Opt. Mater. 5, 1700166 (2017); Sci. Adv. 3, e1602783 (2017)], and colorimetric display. Being able to manipulate the optical properties of metasurfaces will create new regimes of optical physics and impact a broad range of photonic, energy, and biomedical technologies, including new commercial product research and development. Research and development efforts of these artificial thin film materials in promising areas continue to emerge. To capture the latest developments in this important emerging field of optics, it is our pleasure to introduce the Chinese Optics Letters Special Issue on Advances in Metasurface with contributions from scientists around the world who are active in this field.
Chinese Optics Letters
  • Publication Date: May. 10, 2018
  • Vol. 16, Issue 5, 050001 (2018)
High-efficiency multi-wavelength metasurface with complete independent phase control
Jing Yan, Yinghui Guo, Mingbo Pu, Xiong Li, Xiaoliang Ma, and Xiangang Luo
As a consequence of Kramers–Kronig relations, the wavelength-dependent behavior of the metasurface is one of the critical limitations in existing metasurface structures, which reduces the design freedom among different wavelengths. Here, we present an approach to construct a high-efficiency multi-wavelength metasurface with independent phase control by coding different wavelengths into orthogonal polarizations. As proof of the concept, two dual-band metasurfaces have been proposed and numerically demonstrated by multiple vortex beam generation in near-field and polarization multiplexing achromatic beam deflection. Furthermore, simulated results show that the proposed metasurface exhibits high transmission efficiency at both wavelengths, which may find widespread applications in subwavelength electromagnetics.
Chinese Optics Letters
  • Publication Date: May. 10, 2018
  • Vol. 16, Issue 5, 050003 (2018)
Optical cavity resonance with magnetized plasma
Dongyang Wang, Jiaguang Han, and Shuang Zhang
Indefinite media with mixed signs of dielectric tensor elements possess unbounded equifrequency surfaces that have been utilized for diverse applications such as superimaging, enhanced spontaneous emission, and thermal radiation. One particularly interesting application of indefinite media is an optical cavity supporting anomalous scaling laws. In this Letter, we show that by replacing an indefinite medium with magnetized plasma one can construct a tunable indefinite cavity. The magnetized plasma model is based on realistic semiconductor material properties at terahertz frequencies that show hyperbolic dispersion in a certain frequency regime. The hyperbolic dispersion features are utilized for the design of optical cavities. Dramatically different sizes of cavities can support the same resonance mode at the same frequency. For a cavity of fixed size, the anomalous scaling law between the resonance frequency and mode number is confirmed. The resonance frequency can be strongly modulated by changing the strength of the applied magnetic field. The proposed model provides active controllability of terahertz resonances on the deep subwavelength scale with realistic semiconductor materials.
Chinese Optics Letters
  • Publication Date: May. 10, 2018
  • Vol. 16, Issue 5, 050005 (2018)
Metasurfaces enabling structured light manipulation: advances and perspectives [Invited]
Jian Wang
Chinese Optics Letters
  • Publication Date: May. 10, 2018
  • Vol. 16, Issue 5, 050006 (2018)
Fabrication of electrically contacted plasmonic Schottky nanoantennas on silicon
Mohammad Alavirad, Anthony Olivieri, Langis Roy, and Pierre Berini
We fabricate Schottky contact photodetectors based on electrically contacted Au nanoantennas on p-Si for the plasmonic detection of sub-bandgap photons in the optical communications wavelength range. Based on a physical model for the internal photoemission of hot carriers, photons coupled onto the Au nanoantennas excite resonant plasmons, which decay into energetic “hot” holes emitted over the Schottky barrier at the Au/p-Si interface, resulting in a photocurrent. In our device, the active Schottky area consists of Au/p-Si contact and is very small, whereas the probing pad for external electrical interconnection is larger but consists of Au/Ti/p-Si contact having a comparatively higher Schottky barrier, thus producing negligible photo and dark currents. We describe fabrication that involves an electron-beam lithography step overlaid with photolithography. This highly compact component is very promising for applications in high-density Si photonics.
Chinese Optics Letters
  • Publication Date: May. 10, 2018
  • Vol. 16, Issue 5, 050007 (2018)
Enhancing magnetic dipole emission with magnetic metamaterials
Shang Sun, Chen Zhang, Haitao Zhang, Yisheng Gao, Ningbo Yi, Qinghai Song, and Shumin Xiao
Magnetic dipole (MD) transitions are important for a range of technologies from quantum light sources and displays to lasers and bio-probes. However, the typical MD transitions are much weaker than their electric counterparts and are usually neglected in practical applications. Herein, we experimentally demonstrate that the MD transitions can be significantly enhanced by the well-developed magnetic metamaterials in the visible optical range. The magnetic metamaterials consist of silver nanostrips and a thick silver film, which are separated with an Eu3+:polymethyl methacrylate (PMMA) film. By controlling the thickness of the Eu3+:PMMA film, the magnetic resonance has been tuned to match the emission wavelength of MDs. Consequently, the intensity of MD emission has been significantly increased by around 30 times at the magnetic resonance wavelength, whereas the intensity of electric dipole emission is well-preserved. The corresponding numerical calculations reveal that the enhancement is directly generated by the magnetic resonance, which strongly increases the magnetic local density of states around the MD emitter and can efficiently radiate the MD emission into the far field. This is the first demonstration, to the best of our knowledge, that MD transitions can be improved by an additional degree of magnetic freedom, and we believe this research shall pave a new route towards bright magnetic emitters and their potential applications.
Chinese Optics Letters
  • Publication Date: May. 10, 2018
  • Vol. 16, Issue 5, 050008 (2018)
Deflection angle switching with a metasurface based on phase-change nanorods [Invited]
Chulsoo Choi, Sun-Je Kim, Jeong-Geun Yun, Jangwoon Sung, Seoul-Yeol Lee, and Byoungho Lee
Chinese Optics Letters
  • Publication Date: May. 10, 2018
  • Vol. 16, Issue 5, 050009 (2018)

Chinese Optics Letters (COL) invites original manuscript submissions for a Special Issue on Advances in Metasurfaces to be published in May 2018. Metasurface refers to a type of artificial thin film materials with sub-wavelength features that can generate desired and/or new optical phenomena. The past decade has witnessed significant advances in metasurface ranging from fundamental physics to nanomanufacturing methods and practical application. Typical research efforts include wave-front engineering and focusing, polarization manipulation, light trapping and localization, absorption engineering and colorimetric display. Being able to manipulate the optical properties of metasurfaces will create new regimes of optical physics and impact a broad range of photonic, energy and biomedical technologies including new commercial product research and development. This special issue will include excellent review articles and original contributions covering the rapid advances and tremendous breadth of this emerging technical area.