The University of St Andrews

Research@StAndrews:FullText >
Physics & Astronomy (School of) >
Physics & Astronomy >
Physics & Astronomy Theses >

Please use this identifier to cite or link to this item:
This item has been viewed 9 times in the last year. View Statistics

Files in This Item:

File Description SizeFormat
David M Gherardi PhD thesis.PDF24.72 MBAdobe PDFView/Open
Title: Studies of particle and atom manipulation using free space light beams and photonic crystal fibres
Authors: Gherardi, David Mark
Supervisors: Dholakia, Kishan
Keywords: Optical manipulation
Photonic crystal fibre
Atom guiding
Large mode area fibre
Spatial light modulator
Laguerre- Gaussian
Laser cooling
Endlessly single-mode photonic crystal fibre
White light
Dual-beam fibre trap
Optical conveyor belt
Optical fibre
Hot-wire detector
Hollow-core photonic crystal fibre
Photonic bandgap fibre
Issue Date: 26-Jun-2009
Abstract: Light can exert optical forces on matter. In the macroscopic world these forces are minuscule, but on the microscopic or atomic scale, these forces are large enough to trap and manipulate particles. They may even be used to cool atoms to a fraction of a degree above absolute zero. This thesis details a number of experiments concerned with the optical manipulation of atoms and micron-size particles using free space light beams and photonic crystal fibres. Two atom guiding experiments are described. In the first experiment, a spatial light modulator is used to generate higher blue-detuned azimuthal Laguerre-Gaussian LG) beams, which are annular beams with a hollow core. These LG beams are then used to guide laser cooled rubidium-85 atoms within the dark core over a distance of 30 mm. The second atom guiding experiment involves attempting to guide laser cooled and thermal rubidium atoms through a hollow-core photonic crystal fibre using red-detuned light. Hollow-core photonic crystal fibres are fibres that are able to guide light with low attenuation within a hollow core. For this experiment a hot wire detection system was designed, along with a number of complex vacuum systems. The first dual-beam fibre trap for micron-size particles constructed using endlessly single-mode photonic crystal fibre (ESM-PCF) is described. The characteristics of dual-beam fibre traps are governed by the fibres used. As ESM-PCF has considerably different properties in comparison to conventional single- or multimode fibres, this dual beam ESM-PCF trap exhibits some novel characteristics. I show that the dual beam ESM-PCF trap can form trapping, repulsive and line potentials; an interference-free ‘white light’ trap; and a dual-wavelength optical conveyor belt.
Type: Thesis
Publisher: University of St Andrews
Appears in Collections:Physics & Astronomy Theses

This item is protected by original copyright

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


DSpace Software Copyright © 2002-2012  Duraspace - Feedback
For help contact: | Copyright for this page belongs to St Andrews University Library | Terms and Conditions (Cookies)