1
|
Fang N, Wu C, Zhang Y, Li Z, Zhou Z. Perspectives: Light Control of Magnetism and Device Development. ACS NANO 2024; 18:8600-8625. [PMID: 38469753 DOI: 10.1021/acsnano.3c13002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Accurately controlling magnetic and spin states presents a significant challenge in spintronics, especially as demands for higher data storage density and increased processing speeds grow. Approaches such as light control are gradually supplanting traditional magnetic field methods. Traditionally, the modulation of magnetism was predominantly achieved through polarized light with the help of ultrafast light technologies. With the growing demand for energy efficiency and multifunctionality in spintronic devices, integrating photovoltaic materials into magnetoelectric systems has introduced more physical effects. This development suggests that sunlight will play an increasingly pivotal role in manipulating spin orientation in the future. This review introduces and concludes the influence of various light types on magnetism, exploring mechanisms such as magneto-optical (MO) effects, light-induced magnetic phase transitions, and spin photovoltaic effects. This review briefly summarizes recent advancements in the light control of magnetism, especially sunlight, and their potential applications, providing an optimistic perspective on future research directions in this area.
Collapse
Affiliation(s)
- Ning Fang
- School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China
| | - Changqing Wu
- School of Environmental Science and Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Yuzhe Zhang
- School of Environmental Science and Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Zhongyu Li
- School of Environmental Science and Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Ziyao Zhou
- School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China
| |
Collapse
|
2
|
Zerbib M, Romanet M, Sylvestre T, Wolff C, Stiller B, Beugnot JC, Phan Huy K. Spin-orbit interaction in nanofiber-based Brillouin scattering. OPTICS EXPRESS 2023; 31:22284-22295. [PMID: 37475343 DOI: 10.1364/oe.486550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 04/27/2023] [Indexed: 07/22/2023]
Abstract
Angular momentum is an important physical property that plays a key role in light-matter interactions, such as spin-orbit interaction. Here, we investigate theoretically and experimentally the spin-orbit interaction between a circularly polarized optical (spin) and a transverse vortex acoustic wave (orbital) using Brillouin backscattering in a silica optical nanofiber. We specifically explore the state of polarization of Brillouin backscattering induced by the TR21 torso-radial vortex acoustic mode that carries an orbital angular momentum. Using a full-vectorial theoretical model, we predict and observe two operating regimes for which the backscattered Brillouin signal is either depolarized or circularly polarized, depending on the input pump polarization. We demonstrate that when the pump is circularly polarized and thus carries a spin angular momentum, the backscattered signal undergoes a handedness reversal of circular polarization due to opto-acoustic spin-orbit interaction and the conservation of overall angular momentum.
Collapse
|
3
|
Tang X, Kuai Y, Fan Z, Zhang Z, Zhang D. Retrieving the subwavelength cross-section of dielectric nanowires with asymmetric excitation of Bloch surface waves. Phys Chem Chem Phys 2023; 25:7711-7718. [PMID: 36876861 DOI: 10.1039/d3cp00206c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Optical microscopy with a diffraction limit cannot distinguish nanowires with sectional dimensions close to or smaller than the optical resolution. Here, we propose a scheme to retrieve the subwavelength cross-section of nanowires based on the asymmetric excitation of Bloch surface waves (BSWs). Leakage radiation microscopy is used to observe the propagation of BSWs at the surface and to collect far-field scattering patterns in the substrate. A model of linear dipoles induced by tilted incident light is built to explain the directional imbalance of BSWs. It shows the potential capability in precisely resolving the subwavelength cross-section of nanowires from far-field scattering without the need for complex algorithms. Through comparing the nanowire widths measured by this method and those measured by scanning electron microscopy (SEM), the transverse resolutions of the widths of two series of nanowires with heights 55 nm and 80 nm are about 4.38 nm and 6.83 nm. All results in this work demonstrate that the new non-resonant far-field optical technology has potential application in metrology measurements with high precision by taking care of the inverse process of light-matter interaction.
Collapse
Affiliation(s)
- Xi Tang
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China.
| | - Yan Kuai
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China.
| | - Zetao Fan
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China.
| | - Zhiyu Zhang
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China.
| | - Douguo Zhang
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China.
| |
Collapse
|
4
|
Luo K, Huang Z, Lv X, Qiu W, Guan H, Yang T, Grosjean T, Lu H. Directional Bloch surface wave coupling enabled by magnetic spin-momentum locking of light. NANOSCALE ADVANCES 2023; 5:1664-1671. [PMID: 36926573 PMCID: PMC10012835 DOI: 10.1039/d2na00899h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
We study the magnetic spin-locking of optical surface waves. Through an angular spectrum approach and numerical simulations, we predict that a spinning magnetic dipole develops a directional coupling of light to transverse electric (TE) polarized Bloch surface waves (BSWs). A high-index nanoparticle as a magnetic dipole and nano-coupler is placed on top of a one-dimensional photonic crystal to couple light into BSWs. Upon circularly polarized illumination, it mimics the spinning magnetic dipole. We find that the helicity of the light impinging on the nano-coupler controls the directionality of emerging BSWs. Furthermore, identical silicon strip waveguides are configured on the two sides of the nano-coupler to confine and guide the BSWs. We achieve a directional nano-routing of BSWs with circularly polarized illumination. Such a directional coupling phenomenon is proved to be solely mediated by the optical magnetic field. This offers opportunities for directional switching and polarization sorting by controlling optical flows in ultra-compact architectures and enables the investigation of the magnetic polarization properties of light.
Collapse
Affiliation(s)
- Kaiwen Luo
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Department of Optoelectronic Engineering, Jinan University Guangzhou 510632 China
| | - Zhijing Huang
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Department of Optoelectronic Engineering, Jinan University Guangzhou 510632 China
- School of Electronics and Communication, Guangdong Mechanical and Electrical Polytechnic Guangzhou 510550 China
| | - Xianpeng Lv
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Department of Optoelectronic Engineering, Jinan University Guangzhou 510632 China
| | - Wentao Qiu
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Department of Optoelectronic Engineering, Jinan University Guangzhou 510632 China
| | - Heyuan Guan
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Department of Optoelectronic Engineering, Jinan University Guangzhou 510632 China
| | - Tiefeng Yang
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Department of Optoelectronic Engineering, Jinan University Guangzhou 510632 China
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University Guangzhou 510632 China
| | - Thierry Grosjean
- CNRS, FEMTO-ST Institute UMR 6174, Université Bourgogne Franche-Comté Besançon 25000 France
| | - Huihui Lu
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Department of Optoelectronic Engineering, Jinan University Guangzhou 510632 China
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University Guangzhou 510632 China
| |
Collapse
|
5
|
Meng F, Yang A, Du K, Jia F, Lei X, Mei T, Du L, Yuan X. Measuring the magnetic topological spin structure of light using an anapole probe. LIGHT, SCIENCE & APPLICATIONS 2022; 11:287. [PMID: 36202794 PMCID: PMC9537154 DOI: 10.1038/s41377-022-00970-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 07/22/2022] [Accepted: 08/25/2022] [Indexed: 06/16/2023]
Abstract
Topological spin structures of light, including the Skyrmion, Meron, and bi-Meron, are intriguing optical phenomena that arise from spin-orbit coupling. They have promising potential applications in nano-metrology, data storage, super-resolved imaging and chiral detection. Aside from the electric part of optical spin, of equal importance is the magnetic part, particularly the H-type electromagnetic modes for which the spin topological properties of the field are dominated by the magnetic field. However, their observation and measurement remains absent and faces difficult challenges. Here, we design a unique type of anapole probe to measure specifically the photonic spin structures dominated by magnetic fields. The probe is composed of an Ag-core and Si-shell nanosphere, which manifests as a pure magnetic dipole with no electric response. The effectiveness of the method was validated by characterizing the magnetic field distributions of various focused vector beams. It was subsequently employed to measure the magnetic topological spin structures, including individual Skyrmions and Meron/Skyrmion lattices for the first time. The proposed method may be a powerful tool to characterize the magnetic properties of optical spin and valuable in advancing spin photonics.
Collapse
Affiliation(s)
- Fanfei Meng
- Nanophotonics Research Centre, Institute of Microscale Optoelectronics, Shenzhen University, 518060, Shenzhen, China
| | - Aiping Yang
- Nanophotonics Research Centre, Institute of Microscale Optoelectronics, Shenzhen University, 518060, Shenzhen, China
| | - Kang Du
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, 710129, Xi'an, China
| | - Fengyang Jia
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, 710129, Xi'an, China
| | - Xinrui Lei
- Nanophotonics Research Centre, Institute of Microscale Optoelectronics, Shenzhen University, 518060, Shenzhen, China
| | - Ting Mei
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, 710129, Xi'an, China
| | - Luping Du
- Nanophotonics Research Centre, Institute of Microscale Optoelectronics, Shenzhen University, 518060, Shenzhen, China.
| | - Xiaocong Yuan
- Nanophotonics Research Centre, Institute of Microscale Optoelectronics, Shenzhen University, 518060, Shenzhen, China.
| |
Collapse
|
6
|
Kostina N, Petrov M, Bobrovs V, Shalin AS. Optical pulling and pushing forces via Bloch surface waves. OPTICS LETTERS 2022; 47:4592-4595. [PMID: 36107040 DOI: 10.1364/ol.464037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
For flexible tailoring of optical forces, as well as for extraordinary optomechanical effects, additional degrees of freedom should be introduced into a system. Here, we demonstrate that photonic crystals are a versatile platform for optical manipulation due to both Bloch surface waves (BSWs) and the complex character of the reflection coefficient paving a way for controlled optomechanical interactions. We demonstrate enhanced pulling and pushing transversal optical forces acting on a single dipolar bead above a one-dimensional photonic crystal due to directional excitation of BSWs. Our results demonstrate angle- or wavelength-assisted switching between BSW-induced optical pulling and pushing forces. Easy to fabricate for any desired spectral range, photonic crystals are shown to be prospective for precise optical sorting of nanoparticles, which are difficult to sort with conventional optomechanical methods. Our approach opens opportunities for novel, to the best of our knowledge, optical manipulation schemes and platforms, and enhanced light-matter interaction in optical trapping setups.
Collapse
|
7
|
Chen Z, Zhang H, Zhang X, Li H, Yang J, Zhang W, Xi L, Tang X. Symmetric spin splitting of elliptically polarized vortex beams reflected at air-gold interface via pseudo-Brewster angle. OPTICS EXPRESS 2020; 28:29529-29539. [PMID: 33114851 DOI: 10.1364/oe.403916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
A simple expression of the transverse spatial spin splitting of light-carrying intrinsic orbital angular momentum (IOAM) is theoretically derived for reflections at strong absorbing media surfaces. By introducing an asymmetric spin splitting (ASS) factor, the transverse spatial symmetric spin splitting (SSS) and ASS of an arbitrary polarized vortex beam can be distinguished. Here, the transverse spatial SSS of an elliptically polarized vortex beam with a phase difference of 90° is predicted when the incident angle is close to the pseudo-Brewster angle. Remarkably, the larger transverse spatial SSS reaches 1100 nm for the incident circularly polarized LG beam with l=3. It is noteworthy that the transverse spatial SSS can be flexibly manipulated by changing the polarized angle, meaning it is theoretically possible to realize fully polarization-controllable transverse spatial SSS for elliptically polarized incident vortex beams. These results could potentially be applied to precision polarization metrology and edge-enhanced imaging.
Collapse
|
8
|
Stella U, Grosjean T, De Leo N, Boarino L, Munzert P, Lakowicz JR, Descrovi E. Vortex Beam Generation by Spin-Orbit Interaction with Bloch Surface Waves. ACS PHOTONICS 2020; 7:774-783. [PMID: 33644254 PMCID: PMC7901667 DOI: 10.1021/acsphotonics.9b01625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Indexed: 05/27/2023]
Abstract
Axis-symmetric grooves milled in metallic slabs have been demonstrated to promote the transfer of Orbital Angular Momentum (OAM) from far- to near-field and vice versa, thanks to spin-orbit coupling effects involving Surface Plasmons (SP). However, the high absorption losses and the polarization constraints, which are intrinsic in plasmonic structures, limit their effectiveness for applications in the visible spectrum, particularly if emitters located in close proximity to the metallic surface are concerned. Here, an alternative mechanism for vortex beam generation is presented, wherein a free-space radiation possessing OAM is obtained by diffraction of Bloch Surface Waves (BSWs) on a dielectric multilayer. A circularly polarized laser beam is tightly focused on the multilayer surface by means of an immersion optics, such that TE-polarized BSWs are launched radially from the focused spot. While propagating on the multilayer surface, BSWs exhibit a spiral-like wavefront due to the Spin-Orbit Interaction (SOI). A spiral grating surrounding the illumination area provides for the BSW diffraction out-of-plane and imparts an additional azimuthal geometric phase distribution defined by the topological charge of the spiral structure. At infinity, the constructive interference results into free-space beams with defined combinations of polarization and OAM satisfying the conservation of the Total Angular Momentum, based on the incident polarization handedness and the spiral grating topological charge. As an extension of this concept, chiral diffractive structures for BSWs can be used in combination with surface cavities hosting light sources therein.
Collapse
Affiliation(s)
- Ugo Stella
- Department of Applied Science and Technology (DISAT),
Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino,
IT-10129, Italy
| | - Thierry Grosjean
- FEMTO-ST Institute, Université
Bourgogne Franche-Comté, UMR CNRS 6174 15B Avenue des Montboucons,
25030, Besançon, France
| | - Natascia De Leo
- Quantum Research Laboratories & Nanofacility
Piemonte, Advanced Materials Metrology and Life Science Division, Istituto
Nazionale di Ricerca Metrologica (INRiM), Strada delle Cacce 91, Torino,
IT-10135, Italy
| | - Luca Boarino
- Quantum Research Laboratories & Nanofacility
Piemonte, Advanced Materials Metrology and Life Science Division, Istituto
Nazionale di Ricerca Metrologica (INRiM), Strada delle Cacce 91, Torino,
IT-10135, Italy
| | - Peter Munzert
- Fraunhofer Institute for Applied Optics
and Precision Engineering IOF, Albert-Einstein-Str. 7, Jena DE-07745,
Germany
| | - Joseph R. Lakowicz
- Center for Fluorescence Spectroscopy, Department of
Biochemistry and Molecular Biology, University of Maryland School of
Medicine, Baltimore, Maryland 21201, United
States
| | - Emiliano Descrovi
- Department of Applied Science and Technology (DISAT),
Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino,
IT-10129, Italy
| |
Collapse
|
9
|
Feng F, Wei SB, Li L, Min CJ, Yuan XC, Somekh M. Spin-orbit coupling controlled near-field propagation and focusing of Bloch surface wave. OPTICS EXPRESS 2019; 27:27536-27545. [PMID: 31684519 DOI: 10.1364/oe.27.027536] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
Bloch surface wave (BSW) can be considered as the dielectric analogue of surface plasmon polariton (SPP) with less loss since it is sustained at the surface of a truncated dielectric multilayer. As dielectric materials show nearly no ohmic loss, BSW can propagates much farther compared to SPP, and thus is beneficial for planar optical devices. In this paper, we study the spin-orbital interaction between incident beam and BSW. We demonstrate that due to the spin-orbital coupling, the near-field properties of generated BSW can be controlled with a meta-antenna structure. The meta-antenna is composed of two gold nano-antennas oriented at 45° and 135° as a near-field coupler. By careful design of the meta-antenna, the generated BSW can be guided and focused depending on the chirality of the incident beam. Three examples of meta-antennas are demonstrated for chiral sensitive focusing, directional switching and asymmetric focusing. The proposed method can be applied as a design method for low-loss on-chip photonic devices.
Collapse
|
10
|
le Feber B, Sipe JE, Wulf M, Kuipers L, Rotenberg N. A full vectorial mapping of nanophotonic light fields. LIGHT, SCIENCE & APPLICATIONS 2019; 8:28. [PMID: 30854200 PMCID: PMC6403231 DOI: 10.1038/s41377-019-0124-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 12/17/2018] [Accepted: 01/07/2019] [Indexed: 06/09/2023]
Abstract
Light is a union of electric and magnetic fields, and nowhere is the complex relationship between these fields more evident than in the near fields of nanophotonic structures. There, complicated electric and magnetic fields varying over subwavelength scales are generally present, which results in photonic phenomena such as extraordinary optical momentum, superchiral fields, and a complex spatial evolution of optical singularities. An understanding of such phenomena requires nanoscale measurements of the complete optical field vector. Although the sensitivity of near-field scanning optical microscopy to the complete electromagnetic field was recently demonstrated, a separation of different components required a priori knowledge of the sample. Here, we introduce a robust algorithm that can disentangle all six electric and magnetic field components from a single near-field measurement without any numerical modeling of the structure. As examples, we unravel the fields of two prototypical nanophotonic structures: a photonic crystal waveguide and a plasmonic nanowire. These results pave the way for new studies of complex photonic phenomena at the nanoscale and for the design of structures that optimize their optical behavior.
Collapse
Affiliation(s)
- B. le Feber
- Optical Materials Engineering Laboratory, ETH Zürich, 8092 Zurich, Switzerland
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - J. E. Sipe
- Institute for Optical Sciences, University of Toronto, 60 St. George Street, Ontario, M5S 1A7 Canada
| | - M. Wulf
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - L. Kuipers
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
- Kavli Institute of Nanoscience, Department of Quantum Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - N. Rotenberg
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
- Niels Bohr Institute and Center for Hybrid Quantum Networks, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|