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.