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Full-Text Articles in Physics

Miniaturized Iii-V/ Si Hybrid Laser With An Integrated Modulator, Praveen Kumar Singaravelu Sep 2022

Miniaturized Iii-V/ Si Hybrid Laser With An Integrated Modulator, Praveen Kumar Singaravelu

Theses

Light interaction with microscopic and nanoscopic structures enable manipulation of its characteristics which can be used to detect objects in 3D sensing, propel satellites to space using photonic propulsion and transmit data through optical communication. For optical communication, the basic components are lasers, modulators and photodetectors. The development of CMOS microfabrication foundries helps to manufacture silicon-based photonic devices with high yield that is directly co-integrated with electronics in a single chip. However, the lack of emission of photons efficiently in silicon propelled the necessity of hybrid photonic devices that inherits the combined advantage of different materials i.e. functionality and volume. …


Assembly And Detection Of 3-D Qr Codes Through Additive Manufacturing And Terahertz Imaging, Patrick Dunn May 2021

Assembly And Detection Of 3-D Qr Codes Through Additive Manufacturing And Terahertz Imaging, Patrick Dunn

Theses

Automatic identification and data capture, or AIDC, plays a substantial role in contemporary business, advertising, and military needs. The purpose of this study is to generate a potential alternative to current AIDC approaches by constructing three-dimensional plastic tags (or ‘3D QR codes’) using additive manufacturing techniques and interrogate them using Terahertz radiation. 3D Quick Response (QR) codes are designed in 3D computer-aided design software. The QR codes are 3D structures embedded in the printed plastic in which an air gap in the plastic (or an air gap filled in with another type of plastic) indicates a bit of information. Information …


The Primary Volatile Composition Of Comet C/2015 Er61 (Panstarrs), Aaron Butler May 2020

The Primary Volatile Composition Of Comet C/2015 Er61 (Panstarrs), Aaron Butler

Theses

In the outer edges of the solar system exist two regions: the Kuiper belt and Oort cloud. These two regions have a high amount of icy bodies (comets) orbiting the Sun. Comets located within the Oort cloud and Kuiper belt contain an ancient codex to the solar systems contents, before the formation of our solar system. Presented are near-infrared, high-resolution (λ/Δλ ~40000) data obtained from the immersion-grating echelle spectrograph iSHELL at the 3m NASA Infrared Telescope Facility (IRTF) in Maunakea, Hawaii of the Oort cloud comet C/2015 ER61 (PANSTARRS). Observations took place on April 15 and 17 in 2017 while …


Development Of Uv Led Based Lamps With Modular Optical Heads, Ciara O'Hara Jan 2019

Development Of Uv Led Based Lamps With Modular Optical Heads, Ciara O'Hara

Theses

This project was centred around the development of the optical components, and the optimisation of the optical performance, of ProPhotonix Ltd’s Cobra Cure FX series of products. These are high irradiance, high dose, UVA (primarily 395 nm and 365 nm) Light Emitting Diode (LED) lamps designed for curing applications. An initial prototype developed by ProPhotonix, the smallest in the series, the FX1, underwent significant redesign throughout the project, and the two larger lamps, the FX2 and the FX3 were developed during the course of the project. This work primarily consisted in characterising, accurately modelling, and thereby refining, the optical reflector …


Dynamics Of Swept Source Lasers, Ben O'Shaughnessy Jan 2019

Dynamics Of Swept Source Lasers, Ben O'Shaughnessy

Theses

The aim of this thesis is to investigate the dynamics of two kinds of swept source lasers for optical coherence tomography. A mathematical model consisting of a pair of coupled delay differential equations was adapted to study Fourier Domain Mode-Locked (FDML) lasers and short cavity swept source lasers, and to explain experimental observations of these lasers.

The short cavity laser is experimentally observed to produce pulses during the frequency sweep. This ‘sliding frequency mode-locking’ behaviour is reproduced by simulation, which is then used to establish simple relationships between the key parameters of sweep speed, linewidth and output power.

The FDML …


Novel Gaas-Based Materials For Reconfigurable Electro-Modulated Lasers In Optical Interconnects, Jiri Thoma Jan 2014

Novel Gaas-Based Materials For Reconfigurable Electro-Modulated Lasers In Optical Interconnects, Jiri Thoma

Theses

With the rapid commercialization of personal computers and with the ever increasing desire for faster and larger data transfer, there is a strong need to increase network capacity. One solution is to replace standard metallic connections by optical fibers and full optical technologies. Although such technologies exist and are successfully employed in backbone connections, their complexities hinder a wider utilization toward end customers. Therefore, both manufacturing and operational costs are crucial. Integration of several optical components onto a single device chip is the key element. A simplified integration scheme bringing an additional cost reduction is also welcomed. This thesis presents …


Analysis Of Polarimetric Synthetic Aperture Radar And Passive Visible Light Polarimetric Imaging Data Fusion For Remote Sensing Applications, Sanjit Maitra Dec 2013

Analysis Of Polarimetric Synthetic Aperture Radar And Passive Visible Light Polarimetric Imaging Data Fusion For Remote Sensing Applications, Sanjit Maitra

Theses

The recent launch of spaceborne (TerraSAR-X, RADARSAT-2, ALOS-PALSAR, RISAT) and airborne (SIRC, AIRSAR, UAVSAR, PISAR) polarimetric radar sensors, with capability of imaging through day and night in almost all weather conditions, has made polarimetric synthetic aperture radar (PolSAR) image interpretation and analysis an active area of research. PolSAR image classification is sensitive to object orientation and scattering properties. In recent years, significant work has been done in many areas including agriculture, forestry, oceanography, geology, terrain analysis. Visible light passive polarimetric imaging has also emerged as a powerful tool in remote sensing for enhanced information extraction. The intensity image provides information …


Physics-Based Surface Energy Model Optimization For Water Bodies In Cold Climates Using Visible And Calibrated Thermal Infrared Imagery, May V. Casterline Nov 2013

Physics-Based Surface Energy Model Optimization For Water Bodies In Cold Climates Using Visible And Calibrated Thermal Infrared Imagery, May V. Casterline

Theses

When tasked with accurately modeling a water body in a cold climate environment, the complexity of the system being simulated and the numerous parameters affecting the observable outcome pose an arduous task for any modeling effort. The task is increasingly complicated when the body of water is serving as a cooling pond for a power plant and can become partially frozen. The introduction of a heat effluent into the water creates a highly dynamic system whose physical state is not only reactionary to the surrounding environmental conditions, but the industrial facility's operating parameters as well. Both calibrated thermal and visible …


A Mode-Locked Vertical Extended Cavity Surface Emitting Laser, Aoife Deburca Jan 2008

A Mode-Locked Vertical Extended Cavity Surface Emitting Laser, Aoife Deburca

Theses

Surface emitting lasers are a competitive and flexible alternative to edge emitting lasers. The surface-emitting laser has many useful characteristics, which make it beneficial for many applications. These characteristics include the ease of testing during the growth and the fundamental mode output that is effortlessly achieved

The thesis is focused on the Vertical External Cavity Surface Emitting Laser due to its increased flexibility beyond that of the Vertical Cavity Surface Emitting Laser. A wide range of possible parameters are detailed allowing for flexibility in design and applications.

Optically pumped pulsed cavity configurations were investigated in relation to intra-cavity devices and …