Analysis of novel whispering gallery mode cavity

Whispering gallery mode (WGM) is formed when light is trapped inside a circular resonator by continuous total internal reflections. Due to its small mode volume and high quality-factor, WGM has been intensively studied and widely adopted for applications such as sensing, filtering and lasing. Normal...

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Bibliographic Details
Main Author: Zhu, Di
Other Authors: Shum Ping
Format: Final Year Project (FYP)
Language:English
Published: 2013
Subjects:
Online Access:http://hdl.handle.net/10356/53048
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author Zhu, Di
author2 Shum Ping
author_facet Shum Ping
Zhu, Di
author_sort Zhu, Di
collection NTU
description Whispering gallery mode (WGM) is formed when light is trapped inside a circular resonator by continuous total internal reflections. Due to its small mode volume and high quality-factor, WGM has been intensively studied and widely adopted for applications such as sensing, filtering and lasing. Normally, WGM tends to stay near the outer surface of the resonator with a penetration depth no larger than several wavelengths. In this project, in order to enhance the field penetration, we propose a radially graded index WGM cavity design with index profile n=b/r, where n is the refractive index, b is a constant and r is the radial position. The design principle is to gradually increase the refractive index along the radial direction towards the center of the resonator. As a result, the externally coupled light will bend towards the higher index region, i.e. the center of the resonator. The analysis in this report is based on a tubular WGM cavity, which is the commonly adopted liquid core optical ring resonator (LCORR) configuration. With the proposed index profile, the cladding imposes no potential barrier and allows externally coupled evanescent wave to penetrate freely. This design has direct impact on the improvement of the current LCORR, and promises the future implementations of novel liquid-based WGM devices.
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spelling ntu-10356/530482023-07-07T17:11:51Z Analysis of novel whispering gallery mode cavity Zhu, Di Shum Ping School of Electrical and Electronic Engineering A*STAR SIMTech Yu Xia DRNTU::Engineering::Electrical and electronic engineering Whispering gallery mode (WGM) is formed when light is trapped inside a circular resonator by continuous total internal reflections. Due to its small mode volume and high quality-factor, WGM has been intensively studied and widely adopted for applications such as sensing, filtering and lasing. Normally, WGM tends to stay near the outer surface of the resonator with a penetration depth no larger than several wavelengths. In this project, in order to enhance the field penetration, we propose a radially graded index WGM cavity design with index profile n=b/r, where n is the refractive index, b is a constant and r is the radial position. The design principle is to gradually increase the refractive index along the radial direction towards the center of the resonator. As a result, the externally coupled light will bend towards the higher index region, i.e. the center of the resonator. The analysis in this report is based on a tubular WGM cavity, which is the commonly adopted liquid core optical ring resonator (LCORR) configuration. With the proposed index profile, the cladding imposes no potential barrier and allows externally coupled evanescent wave to penetrate freely. This design has direct impact on the improvement of the current LCORR, and promises the future implementations of novel liquid-based WGM devices. Bachelor of Engineering 2013-05-29T08:28:16Z 2013-05-29T08:28:16Z 2013 2013 Final Year Project (FYP) http://hdl.handle.net/10356/53048 en Nanyang Technological University 55 p. application/pdf
spellingShingle DRNTU::Engineering::Electrical and electronic engineering
Zhu, Di
Analysis of novel whispering gallery mode cavity
title Analysis of novel whispering gallery mode cavity
title_full Analysis of novel whispering gallery mode cavity
title_fullStr Analysis of novel whispering gallery mode cavity
title_full_unstemmed Analysis of novel whispering gallery mode cavity
title_short Analysis of novel whispering gallery mode cavity
title_sort analysis of novel whispering gallery mode cavity
topic DRNTU::Engineering::Electrical and electronic engineering
url http://hdl.handle.net/10356/53048
work_keys_str_mv AT zhudi analysisofnovelwhisperinggallerymodecavity