Synopsis

High precision optical measurement requires the development and deployment of highly stable laser sources. The first step towards stabilising a laser is tracking and measuring it's phase noise. This project aims to develop new signal processing and optical methods to track and stabilise cheap noisy lasers for precision measurement.

Research fields

Engineering in Physics;Photonics, Lasers and Nonlinear Optics

Required background

Students will require a background in optics. Prior knowledge of fibre optics and/or digital signal processing is useful but not required.

Description

High precision optical metrology requires the development and deployment of highly coherent laser sources. The wavelength stability of laser sources can be further improved using optical frequency references. Typically, optical frequency references are extremely well aligned optical instruments, and are actively isolated to prevent mechanical and thermal disturbances in order to maintain their performance.

In this project, we aim to use passively stabilised optical fibre interferometers to act as an optical frequency reference. Due to the physical robustness of optical fibre and their passive design, these systems may be engineered to be cheap, compact and field deployable. 

In order to achieve the necessary frequency stability, this project investigates the use of digital signal processing techniques to isolate, suppress or correct for several limiting factors in optical fibre. This includes rejection of scattered light and the correction for polarisation drift. The project will have a digital signal processing component, with optional extensions into theoretical modelling and/or optical system design.