ORCID Profile
0000-0003-2283-9475
Current Organisation
University of South Australia
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Publisher: Walter de Gruyter GmbH
Date: 21-10-2022
Abstract: We demonstrated silicon-on-insulator (SOI)-based high-efficiency metalenses at telecommunication wavelengths that are integrable with a standard 220 nm-thick silicon photonic chip. A negative electron-beam resist (ma-N) was placed on top of the Si nanodisk, providing vertical symmetry to realize high efficiency. A metasurface with a Si/ma-N disk array was numerically investigated to design a metalens that showed that a Si/ma-N metalens could focus the incident beam six times stronger than a Si metalens without ma-N. Metalenses with a thick ma-N layer have been experimentally demonstrated to focus the beam strongly at the focal point and have a long depth of field at telecommunication wavelengths. A short focal length of 10 μm with a wavelength-scale spot diameter of approximately 2.5 μm was realized at 1530 nm. This miniaturized high-efficiency metalens with a short focal length can provide a platform for ultrasensitive sensors on silicon photonic IC.
Publisher: American Physical Society (APS)
Date: 30-06-2011
Publisher: IOP Publishing
Date: 30-06-2011
Publisher: Springer Science and Business Media LLC
Date: 19-11-2013
DOI: 10.1038/NCOMMS3822
Publisher: Wiley
Date: 22-09-2023
Abstract: Metasurfaces consisting of planar subwavelength structures with minimal thickness are appealing to emerging technologies such as integrated optics and photonic chips for their small footprint and compatibility with sophisticated planar nanofabrication techniques. However, reduced dimensionality due to the two‐dimensional nature of a metasurface poses challenges to the adaptation of a few useful methods that have found great success with conventional optics in three‐dimensional space. For instance, Bragg diffraction is the foundation of the well‐established technique of phase‐coded multiplexing in volume holography. It relies on interference among the scattered waves from multiple layers across the thickness of a s le. In this work, despite losing the dimension in thickness, a metasurface is devised to experimentally demonstrate phase‐coded multiplexing by replacing free‐space light with a surface wave in its output. The in‐plane interference along the propagation of the surface wave resembles the Bragg diffraction, thus enabling phase‐coded multiplexing in the two‐dimensional design. An ex le of code‐based all optical routing is also achieved by using a multiplexed metasurface, which could find applications in photonic data processing and communications. This article is protected by copyright. All rights reserved
Publisher: AIP Publishing
Date: 19-04-2021
DOI: 10.1063/5.0046546
Abstract: Recently, tremendous remarkable studies on spin–orbit interactions (SOIs) have attracted interest of scientists across the world in various fields. Among contemporary technologies of probing SOI, photonic metasurfaces have become a prevalent tool to guide and steer wavefront of light at the subwavelength scale. Nevertheless, the discretized nanoantennas of metasurfaces have been plagued for the shortcoming of bandwidth. In contrast to the discretized strategy, symmetric nanorings possessing a continuous phase gradient are exploited in this work. Benefiting from lossless dielectric material and nondispersive characteristic of the Pancharatnam–Berry phase principle, the designer nanorings are viable to realize high efficient spin-to-vortex conversion over a wide spectrum. The nanorings also accomplish a high purity of orbit angular momentum mode, which is of vital importance in many applications. Our findings would be beneficial to delve spin-controllable nanodevices and hold promise for applications of atomic manipulation and optical tweezers.
Publisher: Elsevier BV
Date: 08-2019
Publisher: MDPI AG
Date: 27-12-2022
DOI: 10.3390/PHOTONICS10010027
Abstract: A readily configurable and scalable 2 µm laser source with multi-channel/wavelength fiber output could be advantageous to 2 µm applications such as spectral-beam combination or fiber communications. We report the first experimental realization and characterization of a two-channel holmium-doped zirconium fluoride glass waveguide array laser pumped by a single thulium fiber laser at 1945 nm. Specific laser wavelengths are selected by fiber Bragg gratings (2076.7 nm and 2074.4 nm), and single channel powers of mW are achieved. Design and assembly details, and considerations for future improvements are discussed, including the potential extension to and beyond a 12 channel source.
Publisher: IOP Publishing
Date: 16-01-2014
Publisher: Wiley
Date: 15-04-2019
Abstract: Simultaneous broadband and high efficiency merits of designer metasurfaces are currently attracting widespread attention in the field of nanophotonics. However, contemporary metasurfaces rarely achieve both advantages simultaneously. For the category of transmissive metadevices, plasmonic or conventional dielectric metasurfaces are viable for either broadband operation with relatively low efficiency or high efficiency at only a selection of wavelengths. To overcome this limitation, dielectric nanoarcs are proposed as a means to accomplish two advantages. Continuous nanoarcs support different electromagnetic resonant modes at localized areas for generating phase retardation. Meanwhile, the geometric nature of nanoarc curvature endows the nanoarcs with full phase coverage of 0-2π due to the Pancharatnam-Berry phase principle. Experimentally incorporated with the chiral-detour phase principle, a few compelling functionalities are demonstrated, such as chiral beamsplitting, broadband holography, and helicity-selective holography. The continuous nanoarc metasurfaces prevail over plasmonic or dielectric discretized building block strategies and the findings lead to novel designs of spin-controllable metadevices.
Publisher: IEEE
Date: 10-2013
Publisher: Optica Publishing Group
Date: 28-03-2022
DOI: 10.1364/OE.452945
Abstract: Coupling characteristics between a single mode fiber (SMF) and a waveguide embedded in a glass chip via a graded index fiber (GIF) tip are investigated at a wavelength of 976 nm. The GIF tips comprise a coreless fiber section and a GIF section. A depressed cladding waveguide in a ZBLAN glass chip with a core diameter of 35 μm is coupled with GIF tips that have a range of coreless fiber and GIF lengths. An experimental coupling efficiency as high as 88% is obtained while a numerical simulation predicts 92.9% for the same GIF tip configuration. Since it is measured in the presence of Fresnel reflection, it can be further improved by anti-reflection coating. Additionally, it is demonstrated that a gap can be introduced between the chip waveguide and the GIF tip while maintaining the high coupling efficiency, thus allowing a thin planar optical component to be inserted. The results presented here will enable miniaturization and simplification of photonic chips with integrated waveguides by replacing bulk coupling lenses with integrated optical fibers.
Publisher: AIP Publishing
Date: 31-10-2016
DOI: 10.1063/1.4966666
Abstract: Coupled metal nanostructures supporting localized surface plasmon resonances are represented as a nanoscale optical circuit that takes light fields as inputs and forms linear combinations of them with complex coefficients. The subwavelength arrays of these circuits form a metasurface that performs mathematical operations in two dimension on an incident light field. We demonstrate this concept with subwavelength scale plasmonic circuits that perform difference operations. The metasurface is fabricated from the arrays of coupled gold nanorods where each group of three rods forms the difference circuit. The operation of the metasurface is demonstrated experimentally.
Publisher: Wiley
Date: 18-12-2018
Publisher: Springer Science and Business Media LLC
Date: 14-05-2019
DOI: 10.1038/S41598-019-43914-Z
Abstract: We propose a complementary split-ring resonator (CSRR) for a directional coupling of surface plasmon polaritons. An air-slot split-ring in a gold film is investigated using the finite-difference time-domain method. The normally incident light couples to either a monopole or a dipole SPP depending on the polarization of light. Adjusting the angle of the linear polarization of the incident light enables a one-way propagation of SPPs on the gold film. Theoretical analysis based on the propagation of cylindrical waves from the SPP point source is provided with Hankel function. The propagated power in one direction is obtained to be 30 times higher than the opposite direction with a coupling efficiency of 18.2% from the simulation for an array of the CSRRs. This approach to the directional coupling of SPPs will be advantageous for miniaturizing photonic and plasmonic circuits and devices.
Publisher: The Optical Society
Date: 13-03-2018
DOI: 10.1364/OE.26.007368
Publisher: Wiley
Date: 04-12-2018
Publisher: American Chemical Society (ACS)
Date: 16-06-2017
Publisher: Elsevier BV
Date: 09-2011
Publisher: Wiley
Date: 13-10-2017
Publisher: American Chemical Society (ACS)
Date: 08-10-2018
Publisher: American Physical Society (APS)
Date: 21-06-2021
Publisher: SPIE
Date: 08-03-2023
DOI: 10.1117/12.2649429
Publisher: IOP Publishing
Date: 04-2013
No related grants have been discovered for Yongsop Hwang.