Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.782610
Title: Suppression of noise in classical and quantum optics
Author: Allen, Euan
ISNI:       0000 0004 7968 2154
Awarding Body: University of Bristol
Current Institution: University of Bristol
Date of Award: 2019
Availability of Full Text:
Access from EThOS:
Access from Institution:
Abstract:
Noise is a fundamental feature of quantum mechanics. It also defines the practical limitations of tools used across science and technology, such as sensors or measurement apparatus. In this thesis, we introduce theoretical and experimental work that focusses on reducing noise, from both classical and quantum sources, in a number of different scenarios. We begin by looking at absorbance estimation through the Beer-Lambert law. We introduce a method of reducing the effect of amplitude or intensity noise of the laser source on the produced estimate of the absorbance of the sample. We show that optimising the length of material that the light passes through can nearly entirely mitigate the effects of excess noise on the input optical beam, which limits the improvement gained by applying quantum states (Fock states) to this sensor to around a 20% improvement over the best classical strategy. We show experimental validation of this theory. We also look at an experimental technique for reducing classical amplitude noise in pulsed laser systems, using an asymmetric interferometer. We discuss a number of practical limitations of the scheme and demonstrate how these can be avoided by implementation in solid and hollow-core optical fibre. We show that all of the classical amplitude noise can be removed (in a particular bandwidth) to achieve light that is only limited by quantum fluctuations. We report theoretical and experimental work that show how this technique can be extended to suppress noise in multiple frequency bands. Finally, we investigate practical ways of generating squeezed light in integrated silicon and silicon nitride devices. We show that both platforms display promising signs that they are appropriate to generate squeezing in, but demonstration of quantum noise reduction is yet to be achieved.
Supervisor: Matthews, Jonathan Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.782610  DOI: Not available
Share: