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Zhao L, Yu M. Structural Luneburg lens for broadband cloaking and wave guiding. Sci Rep 2020; 10:14556. [PMID: 32883990 PMCID: PMC7471698 DOI: 10.1038/s41598-020-71124-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/05/2020] [Indexed: 11/29/2022] Open
Abstract
In this paper, we explore the concept of structural Luneburg lens (SLL) as a design framework for performing dynamic structural tailoring to obtain a structural wave cloak and a structural waveguide. The SLL is a graded refractive index lens, which is realized by using a variable thickness structure defined in a thin plate. Due to the thickness variation of the plate, the refractive index decreases radially from the centre to the outer surface of the lens. By taking advantage of the unique capabilities of SLL for flexural wave focusing and collimation, we develop a structural wave cloak and waveguide based on SLLs. The SLL design enables the integration of functional devices into thin-walled structures while preserving the structural characteristics. Analytical, numerical, and experimental studies are carried out to characterize the performance of the SLL cloak and the SLL waveguide. The results demonstrate that these SLL devices exhibit excellent performance for structural wave cloaking and waveguiding over a broadband operating frequency range.
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Affiliation(s)
- Liuxian Zhao
- Institute for Systems Research, University of Maryland, College Park, MD, 20742, USA
| | - Miao Yu
- Institute for Systems Research, University of Maryland, College Park, MD, 20742, USA. .,Department of Mechanical Engineering, University of Maryland, College Park, MD, 20742, USA.
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Augenstein Y, Vetter A, Lahijani BV, Herzig HP, Rockstuhl C, Kim MS. Inverse photonic design of functional elements that focus Bloch surface waves. LIGHT, SCIENCE & APPLICATIONS 2018; 7:104. [PMID: 30564310 PMCID: PMC6289961 DOI: 10.1038/s41377-018-0106-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 11/20/2018] [Accepted: 11/24/2018] [Indexed: 05/03/2023]
Abstract
Bloch surface waves (BSWs) are sustained at the interface of a suitably designed one-dimensional (1D) dielectric photonic crystal and an ambient material. The elements that control the propagation of BSWs are defined by a spatially structured device layer on top of the 1D photonic crystal that locally changes the effective index of the BSW. An example of such an element is a focusing device that squeezes an incident BSW into a tiny space. However, the ability to focus BSWs is limited since the index contrast achievable with the device layer is usually only on the order of Δn≈0.1 for practical reasons. Conventional elements, e.g., discs or triangles, which rely on a photonic nanojet to focus BSWs, operate insufficiently at such a low index contrast. To solve this problem, we utilize an inverse photonic design strategy to attain functional elements that focus BSWs efficiently into spatial domains slightly smaller than half the wavelength. Selected examples of such functional elements are fabricated. Their ability to focus BSWs is experimentally verified by measuring the field distributions with a scanning near-field optical microscope. Our focusing elements are promising ingredients for a future generation of integrated photonic devices that rely on BSWs, e.g., to carry information, or lab-on-chip devices for specific sensing applications.
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Affiliation(s)
- Yannick Augenstein
- Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Andreas Vetter
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
- SUSS MicroOptics SA, Rogues-Terres 61, Hauterive, 2068 Switzerland
| | - Babak Vosoughi Lahijani
- Optics & Photonics Technology Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel, Switzerland
| | - Hans Peter Herzig
- Optics & Photonics Technology Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel, Switzerland
| | - Carsten Rockstuhl
- Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Myun-Sik Kim
- Optics & Photonics Technology Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel, Switzerland
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Wang R, Chen J, Xiang Y, Kuai Y, Wang P, Ming H, Lakowicz JR, Zhang D. Two-Dimensional Photonic Devices based on Bloch Surface Waves with One-Dimensional Grooves. PHYSICAL REVIEW APPLIED 2018; 10:024032. [PMID: 31576366 PMCID: PMC6769415 DOI: 10.1103/physrevapplied.10.024032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Both experiments and simulations show that the polarization state and propagation path of the Bloch surface waves sustained on a dielectric multilayer, can be manipulated with the grooves inscribed on this multilayer. These grooves can be easily producible, accessible and controllable. Various nano-devices for the Bloch surface waves, such as the launcher, beam splitter, reflector, polarization rotator, and even the photonic single-pole double-throw switch, were all experimentally realized with the properly designed grooves, which are consistent with the numerical simulations. The proposed devices will be basic elements for the two-dimensional photonic system, and will find numerous applications, including integrated photonics, molecular sensing, imaging and micro-manipulation.
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Affiliation(s)
- Ruxue Wang
- Institute of Photonics, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P.R. China
| | - Junxue Chen
- School of Science, Southwest University of Science and Technology, Mianyang, Sichuan 621010, P.R. China
| | - Yifeng Xiang
- Institute of Photonics, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P.R. China
| | - Yan Kuai
- Institute of Photonics, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P.R. China
| | - Pei Wang
- Institute of Photonics, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P.R. China
| | - Hai Ming
- Institute of Photonics, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P.R. China
| | - Joseph R. Lakowicz
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Douguo Zhang
- Institute of Photonics, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P.R. China
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