The Library
Enhanced polarisation control and extreme electric fields: advances in terahertz spectroscopy applied to anisotropic materials and magnetic phase transitions
Tools
Tools
Tools
Mosley, C. D. W. (2019) Enhanced polarisation control and extreme electric fields: advances in terahertz spectroscopy applied to anisotropic materials and magnetic phase transitions. PhD thesis, University of Warwick.
|
PDF
WRAP_Theses_Mosley_2019.pdf - Submitted Version - Requires a PDF viewer. Download (31Mb) | Preview |
Official URL: http://webcat.warwick.ac.uk/record=b3714243
Abstract
This thesis reports advances in terahertz time-domain spectroscopy, relating to the development of new techniques and components that enhance the experimentalist's control over the terahertz polarisation state produced by photoconductive emitters, and in utilising the dynamic magnetoelectric response at THz frequencies, in the form of electromagnons, to probe material properties at a transition between two magnetically ordered phases.
Two methods of controlling the terahertz polarisation state are reported: The first method is based upon mechanical rotation of an interdigitated photoconductive emitter, and is implemented in a rotatable-polarisation terahertz time-domain spectrometer, the calibration of which is demonstrated to produce a highly uniform polarisation state at all angles. This method is then demonstrated experimentally to identify the orientations of the normal modes of propagation in the plane of birefringent samples, to extract the full complex refractive index along these directions, and to investigate the optical selection rules of an absorbing material. The second method presents a new photoconductive emitter design, based upon separate interdigitated pixel elements for the generation of the horizontally and vertically polarised components of the terahertz pulses, that permits rotation of the polarisation state solely by electrical control. The design, fabrication and experimental verification of the device is reported, demonstrating polarisation control on timescales orders of magnitude faster than those achievable in mechanical rotation methods.
A method of using the electromagnon response in Cu1
| Item Type: | Thesis (PhD) | ||||
|---|---|---|---|---|---|
| Subjects: | Q Science > QC Physics Q Science > QD Chemistry |
||||
| Library of Congress Subject Headings (LCSH): | Terahertz spectroscopy, Anisotropy, Magnetoresistance, Electromagnetic waves -- Polarization, Photoconductivity | ||||
| Official Date: | August 2019 | ||||
| Dates: |
|
||||
| Institution: | University of Warwick | ||||
| Theses Department: | Department of Physics | ||||
| Thesis Type: | PhD | ||||
| Publication Status: | Unpublished | ||||
| Supervisor(s)/Advisor: | Lloyd-Hughes, James | ||||
| Format of File: | |||||
| Extent: | ix, 165 leaves : illustrations | ||||
| Language: | eng |
Request changes or add full text files to a record
Repository staff actions (login required)
 |
View Item |
Downloads
Downloads per month over past year
