Controlled Lasing in Gallium Nitride Nanowires
type: CreativeWork
description: There is considerable interest in ultra-small coherent light sources. A strong candidate is a semiconductor-nanowire laser, where a single, monolithic nanowire functions simultaneously as an optical microcavity and active medium, leading to an extremely compact and robust laser. Recent advances in nanowire synthesis have enabled realization of optically pumped nanowire lasers in different material systems, including III-V, III-nitride, and II-VI semiconductors. However, due to the limited lasing control techniques, most of the nanowire lasers operate in naturally-occurring multi-mode and randomly polarized states. Lasing control in nanowire lasers is strongly desired for many practical applications. For instance, specifically polarized lasing is desired for atom trapping and biological detection, and single-mode lasing is crucial for applications needing high beam quality and spectral purity such as nanolithography and on-chip communications. Motivated by these practical requirements, this dissertation concentrates on the study of fundamental lasing characteristics and their control in gallium nitride (GaN) nanowire lasers. GaN nanowire lasers typically operate in a combined multi-longitudinal and multi-transverse mode state. Two schemes are introduced here for controlling the optical mode and achieving single-mode operation of the nanowire lasers. The first method involves placing two nanowires side-by-side in contact to form a coupled cavity. The coupled cavity can generate a Vernier effect, which is able to suppress both multi-longitudinal and multi-transverse mode operation, giving rise to the single-mode lasing in these nanowire lasers. For the second method, single-mode lasing is achieved by placing individual GaN nanowires onto gold substrates. The nanowire-gold contact generates a mode-dependent loss, which can strongly attenuate high-order guiding modes and ensure single-mode operation. Additionally, polarization properties of the gallium nitride nanowire l…
abstract: There is considerable interest in ultra-small coherent light sources. A strong candidate is a semiconductor-nanowire laser, where a single, monolithic nanowire functions simultaneously as an optical microcavity and active medium, leading to an extremely compact and robust laser. Recent advances in nanowire synthesis have enabled realization of optically pumped nanowire lasers in different material systems, including III-V, III-nitride, and II-VI semiconductors. However, due to the limited lasing control techniques, most of the nanowire lasers operate in naturally-occurring multi-mode and randomly polarized states. Lasing control in nanowire lasers is strongly desired for many practical applications. For instance, specifically polarized lasing is desired for atom trapping and biological detection, and single-mode lasing is crucial for applications needing high beam quality and spectral purity such as nanolithography and on-chip communications. Motivated by these practical requirements, this dissertation concentrates on the study of fundamental lasing characteristics and their control in gallium nitride (GaN) nanowire lasers. GaN nanowire lasers typically operate in a combined multi-longitudinal and multi-transverse mode state. Two schemes are introduced here for controlling the optical mode and achieving single-mode operation of the nanowire lasers. The first method involves placing two nanowires side-by-side in contact to form a coupled cavity. The coupled cavity can generate a Vernier effect, which is able to suppress both multi-longitudinal and multi-transverse mode operation, giving rise to the single-mode lasing in these nanowire lasers. For the second method, single-mode lasing is achieved by placing individual GaN nanowires onto gold substrates. The nanowire-gold contact generates a mode-dependent loss, which can strongly attenuate high-order guiding modes and ensure single-mode operation. Additionally, polarization properties of the gallium nitride nanowire l…
author: Huiwen, X
language: English
date published: 2013-09-05T07:00:00Z
date modified: 2026-07-24T05:26:35Z
provider: University of New Mexico
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of New Mexico

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1928/23381