Adiabatically Tapered All-Fibre Devices for Mode Manipulation

Abstract

In this thesis we describe all-fibre devices that can be used for manipulating modes in a range of applications. The devices comprise an input and an output system and rely on fibre transitions. If the transition is gradual enough to be adiabatic, we can predict the behaviour of the output system depending only on the characteristics of the input system. Some of these devices work in a mode-selective regime where each input of the device excites a different mode at the output. These devices can be used to increase the data capacity of fibre networks where each mode can be used as an independent data channel. We also demonstrate mode converters that convert light to different higher-order modes of a ribbon fibre and can be used to increase the peak power transmitted in fibre lasers. Finally we describe devices that are non-mode-selective and have several cores. These devices convert the modes of a multimode core to the modes of a rectangular core made from individual fibres. These can be used as a diffraction-limited input to a spectrograph to eliminate modal noise from astronomical measurements.

Date of Award	12 Oct 2016
Original language	English
Awarding Institution	University of Bath
Supervisor	Tim Birks (Supervisor)