Bismuth-doped fibre amplifiers for extended transmission bands in optical communications

About the Project

Supervisory Team: Professor Jayanta Sahu, Professor Johan Nilsson and Dr Yongmin Jung

This project aims to develop advanced bismuth-doped optical fibres with optimised design, fabrication, and material properties. The goal is to realise next-generation ultra-wideband fibre amplifiers and tunable lasers covering the low-loss transmission window of 1250 – 1700nm of silica optical fibres.

Global internet traffic has grown exponentially over the past 2 decades with a predicted growth rate of around 40% year on year. This growth is driven primarily by bandwidth-hungry applications such as cloud computing, Telemedicine, 4K live streaming. Growth is expected to continue in the era of the Internet of Things (IoT) and 5G.

The present optical fibre communication network’s capacity is solely based on the 11THz (C and L bands) gain bandwidth of erbium (Er) doped fibre amplifiers (EDFA) invented 3 decades ago. The scaling of the overall transmission capacity requires next-generation optical fibre amplifiers to further utilise the low-loss window offered by solid- and hollow-core silica optical fibres.

In this project, we aim to develop efficient Bi-doped fibres and to demonstrate next-generation ultra-broadband Bi-doped fibre amplifiers (BDFAs) covering the wavelength regions of 1250-1500nm and 1600-1750nm. In the process of developing Bi-doped fibres, You'll also study spectroscopic properties such as absorption and emission cross-sections to understand the near-IR luminescence in these fibres.

The focus will be on experimental work, but can include simulations and modelling of new amplifiers based on your interests. You'll have access to state-of-the-art fibre fabrication facilities and laboratories at the Optoelectronics Research Centre (ORC). The performance of developed BDFAs will be evaluated in collaboration with our academic partners.

Our research demonstrating a record level of optical gain (40dB), a wide amplification bandwidth (>120nm), and the highest reported gain per unit length (1.42 dB/m from BDFAs has been widely recognised by the scientific community and has attracted considerable attention from the telecommunications and related industries.

Entry requirements

You must have a UK 2:1 honours degree, or its international equivalent.

Fees and funding

Full scholarships include tuition fees, a stipend at the UKRI rate plus 10% ORC enhancement tax-free per annum for up to 3.5 years (totalling £22,858 for 2025/26, rising annually) and a budget of £4200 for things like conference travel.

UK, EU and Horizon Europe students are eligible for scholarships. CSC students are eligible for fee waivers. Funding for other international applicants is very limited and highly competitive. Overseas students who have secured or are seeking external funding are welcome to apply.

For more information, please visit our postgraduate research funding pages.

How to apply

Apply now

You need to:

• choose programme type (Research), 2026/27, Faculty of Engineering and Physical Sciences
• select Full time or Part time
• search for programme PhD ORC (7097)
• add name of the supervisor in section 2 of the application

Applications should include:

• your CV (resumé)
• 2 academic references
• degree transcripts and certificates to date
• English language qualification (if applicable)

Contact us

Faculty of Engineering and Physical Sciences

If you have a general question, feps-pgr-apply@soton.ac.uk.

Project leader

If you wish to discuss any details of the project informally, please contact jks@orc.soton.ac.uk.