Development of Specialty Optical Fibres for High-power Eye-safe Fibre Lasers

About the Project

Supervisory Team: Professor Jayanta Sahu and Professor Johan Nilsson

This PhD project will focus on advancing the fabrication of active optical fibres, optimising their material properties, and developing specialised coatings to achieve excellent laser efficiency, good beam quality, and effective thermal management for high-power fibre lasers and amplifiers operating at the eye-safe wavelength of 1.55 micrometers (μm) .

Specialty optical fibres form the foundation of numerous technological advancements across diverse fields, including high-power laser systems, advanced manufacturing, and optical communications. Each of these application domains depends critically on the development of fibres with tailored properties to satisfy increasingly demanding performance requirements.

In particular, the power scaling of fibre lasers operating at eye-safe wavelengths (typically around 1.5–2 µm) is strongly influenced by the fibre design and the material properties of both the core and coating, which determine the limits of power handling and thermal management. Meeting these requirements demands advanced fibre fabrication processes that go beyond current industry standards.

In this PhD project, we aim to develop novel optical fibre materials and fabrication techniques for advanced erbium-doped fibres (EDFs) with tailored dopant profiles and large cores, supporting power scaling of pulsed and CW lasers and amplifiers at 1.55 µm. Special fibre coatings will be applied to ensure efficient thermal management at high average powers (several hundred watts) to enhance the robustness and reliability of fibre lasers for practical applications.

The student will also perform a detailed spectroscopic characterisation of the fabricated fibres and participate in testing their performance in high-power lasers.

The research program will provide the candidate with numerous training opportunities, ranging from cleanroom-based fibre fabrication techniques to spectroscopic characterisation of active fibres and fibre lasers.

Entry requirements

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

How to apply

Apply now

• programme type: research
• academic year: 2026/27
• if you will be full time or part time
• faculty: Engineering and Physical Sciences
• search for programme PhD ORC (7097)
• please add the name of the supervisor in section 2 of the application.

Applications should include:

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