Prof. Dr. Lien-Wen Chen

Committee: International Scientific Committee of Mechanical and Mechatronics Engineering
University: National Cheng Kung University
Department: Department of Mechanical Engineering
Research Fields: magnetic photonic crystal, refractive index sensor, sensitivity, high-resolution,

Publications

3 Analysis of Scattering Behavior in the Cavity of Phononic Crystals with Archimedean Tilings

Authors: I-Ling Chang, Lien-Wen Chen, Hsiang-Wen Tang, Yi-Hua Chen

Abstract:

The defect mode of two-dimensional phononic crystals with Archimedean tilings was explored in the present study. Finite element method and supercell method were used to obtain dispersion relation of phononic crystals. The simulations of the acoustic wave propagation within phononic crystals are demonstrated. Around the cavity which is created by removing several cylinders in the perfect Archimedean tilings, whispering-gallery mode (WGM) can be observed. The effects of the cavity geometry on the WGM modes are investigated. The WGM modes with high Q-factor and high cavity pressure can be obtained by phononic crystals with Archimedean tilings.

Keywords: defect mode, Archimedean tilings, phononic crystals, whispering- gallery modes

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2 A High-Resolution Refractive Index Sensor Based on a Magnetic Photonic Crystal

Authors: I-Ling Chang, Lien-Wen Chen, Ti-An Tsai, Chun-Chih Wang, Hung-Wen Wang

Abstract:

In this study, we demonstrate a high-resolution refractive index sensor based on a Magnetic Photonic Crystal (MPC) composed of a triangular lattice array of air holes embedded in Si matrix. A microcavity is created by changing the radius of an air hole in the middle of the photonic crystal. The cavity filled with gyrotropic materials can serve as a refractive index sensor. The shift of the resonant frequency of the sensor is obtained numerically using finite difference time domain method under different ambient conditions having refractive index from n = 1.0 to n = 1.1. The numerical results show that a tiny change in refractive index of  Δn = 0.0001 is distinguishable. In addition, the spectral response of the MPC sensor is studied while an external magnetic field is present. The results show that the MPC sensor exhibits a dramatic improvement in resolution.

Keywords: Sensitivity, magnetic photonic crystal, refractive index sensor, high-resolution

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1 Thermal Carpet Cloaking Achieved by Layered Metamaterial

Authors: Lien-Wen Chen, Bang-Shiuh Chen

Abstract:

We have devised a thermal carpet cloak theoretically and implemented in silicon using layered metamaterial. The layered metamaterial is composed of single crystalline silicon and its phononic crystal. The design is based on a coordinate transformation. We demonstrate the result with numerical simulation. Great cloaking performance is achieved as a thermal insulator is well hidden under the thermal carpet cloak. We also show that the thermal carpet cloak can even the temperature on irregular surface. Using thermal carpet cloak to manipulate the heat conduction is effective because of its low complexity.

Keywords: cloaking, Metamaterial, Heat Conduction, phononic crystal

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Abstracts

2 Analysis of Scattering Behavior in the Cavity of Phononic Crystals with Archimedean Tilings

Authors: I-Ling Chang, Lien-Wen Chen, Hsiang-Wen Tang, Yi-Hua Chen

Abstract:

The defect mode of two-dimensional phononic crystals with Archimedean tilings was explored in the present study. Finite element method and supercell method were used to obtain dispersion relation of phononic crystals. The simulations of the acoustic wave propagation within phononic crystals are demonstrated. Around the cavity which is created by removing several cylinders in the perfect Archimedean tilings, whispering-gallery mode (WGM) can be observed. The effects of the cavity geometry on the WGM modes are investigated. The WGM modes with high Q-factor and high cavity pressure can be obtained by phononic crystals with Archimedean tilings.

Keywords: defect mode, Archimedean tilings, phononic crystals, whispering-gallery modes

Procedia PDF Downloads 273
1 A High-Resolution Refractive Index Sensor Based on a Magnetic Photonic Crystal

Authors: I-Ling Chang, Lien-Wen Chen, Ti-An Tsai, Chun-Chih Wang, Hung-Wen Wang

Abstract:

In this study, we demonstrate a high-resolution refractive index sensor based on a magnetic photonic crystal (MPC) composed of a triangular lattice array of air holes embedded in Si matrix. A microcavity is created by changing the radius of an air hole in the middle of the photonic crystal. The cavity filled with gyrotropic materials can serve as a refractive index sensor. The shift of the resonant frequency of the sensor is obtained numerically using finite difference time domain method under different ambient conditions having refractive index from n = 1.0 to n = 1.1. The numerical results show that a tiny change in refractive index of Δn = 0.0001 is distinguishable. In addition, the spectral response of the MPC sensor is studied while an external magnetic field is present. The results show that the MPC sensor exhibits a dramatic improvement in resolution.

Keywords: Sensitivity, magnetic photonic crystal, refractive index sensor, high-resolution

Procedia PDF Downloads 372