Active Physics & Astronomy Materials & Manufacturing

Raman Distributed Feedback Fibre Lasers

Funder EPSRC (part of UKRI)
Recipient organisation University of Southampton
Funding £812K
Period Mar 2025 — Mar 2028

In plain English

AI plain-English summary

A new type of fibre laser, just centimetres long, will produce light with a linewidth of less than a thousandth of a nanometre across the entire silica transmission window. Today’s rare-earth doped fibre lasers are limited in the wavelengths they can reach and often suffer from noise. This project builds a laser that uses Raman gain—the same effect that makes fibre-optic cables amplify signals—inside a precisely etched Bragg grating. The result is a compact, low-noise, single-frequency source that can be tuned to any wavelength where silica is transparent, from the visible to the infrared. If successful, these Raman distributed feedback lasers will fill a gap where no such sources currently exist. They will enable LIDAR for atmospheric monitoring, high-resolution spectroscopy for trace-gas sensing in environmental science, and nonlinear optics experiments such as four-wave mixing. The team will also demonstrate direct diode pumping, reducing cost and complexity for integration into instruments. This is fundamental photonics research with a clear engineering goal. Past work on fibre lasers and Raman amplification has already transformed telecommunications and sensing. This project extends that capability into new wavelength bands, potentially improving the sensitivity and reach of systems that quietly monitor air quality, map wind fields, or drive precision manufacturing.

View original technical description
This proposal is focused on fibre lasers and will develop a new class of compact (centimetre length), narrow-linewidth (kHz and sub-kHz) fibre laser based on fibre Bragg gratings and Raman gain in silica-based fibres, the so-called Raman Distributed Feedback (R-DFB) fibre laser. This type of laser exhibits superior performance to those of standard rare-earth doped DFB fibre lasers in terms of efficiency, coherence length, low noise-level, and wavelength agility, and will allow for unconstrained single-frequency wavelength operation across the full transmission-window of silica. Continuous wave (CW) output power values up to 100mW will be targeted and the work will demonstrate R-DFB lasers in both germanosilicate and phosphosilicate fibres, each of which allows for different levels of Raman frequency shifts, at wavelengths applicable to LIDAR, high-spectral brightness and long coherence length applications incl., nonlinear optics applications, in particular four-wave-mixing (FWM), and spectroscopic sensing incl., trace sensing of targeted molecular species of importance for environmental monitoring. For ease of operation and integration, and for reduced complexity and cost, the work will also demonstrate direct laser diode-pumping of the developed R-DFB lasers. These lasers will help realise an increasingly important unmet need for low noise kHz linewidth sources in several wavelength bands where currently no such sources are available.

View the original record at the funder ↗

Researchers

Morten Ibsen (Principal Investigator)

Related Research

Grants with similar aims, by meaning.

Tuneable, visible, integrated, fibre-based sources with selectable pulsewidth and repetition rate for biophotonics applications
Bismuth-doped fibre laser systems
Cladding-pumped fibre Raman lasers and amplifiers
Wavelength tunable, pulsewidth selectable, repetition rate variable, fibre based infra red source
Development of rare-earth-doped large-core photonic bandgap fibre technology for power-scaling at challenging wavelengths

Original classification

Research and Innovation

Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.