IN THIS SECTION
Advanced Solid-State Sources and Applications
High-power fibre lasers and amplifiers:
Fibre lasers and amplifiers were once regarded as relatively low power devices with application areas dominated by optical communications and sensing. However, over the last decade there has been increasing recognition that rare-earth-ion doped fibres also offer a very attractive route to very high laser powers.
The chief benefits of a fibre gain medium are derived directly from its geometry which offers very simple thermal management and a high degree of immunity from thermal effects which are often so detrimental to laser performance in other types of laser. This feature in combination with the use of cladding-pumping and high-brightness diode pump sources (see below) has resulted in a dramatic rise in the output power fibre-based laser and amplifier sources. In fact, the rate of progress has been so rapid that it has fuelled thoughts that fibre laser technology will replace conventional solid-state laser technology in many fields of application. In spite of these developments there are still many challenges, as well as opportunities to improve performance, extend the range of operating wavelengths and to increase functionality.
Our current research is exploring the use of novel fibre geometries including helical-core (or twisted-core) fibres, ribbon fibres, multi-core fibres, cladding-pumped long-rod fibres and beam combination schemes to allow scaling to higher powers and higher pulse energies whilst preserving excellent beam quality and the well-behaved operating characteristics of lower power devices.
High-power fibre-based superfluorescent sources:
Traditionally, these sources have been restricted to operation at rather low power levels for a number of reasons.
The main objective of our research in this area is to investigate new fibre architectures for scaling to very high power levels ~1Ám, ~1.5Ám and ~ 2Ám wavelength regimes whilst avoiding unwanted (parasitic) lasing, and to explore new applications for these unique light sources.
Versatile Infrared Laser source for Low-cost Analysis of Gas Emissions (VILLAGE):
The main objective of this project is to develop a widely-tunable mid-infrared source of high spectral purity for the next generation of multi-gas analysers based on high-resolution spectroscopic techniques for accurate measurements of polluting gases generated by industrial processes. Particular emphasis will be directed towards developing a cost-effective means for measuring concentration levels of the gases believed to contribute to global warming. The range of operating wavelengths required is very difficult to achieve via conventional approaches.
The VILLAGE technical approach will bring together some of the latest developments in the field of fibre lasers, nonlinear materials, nonlinear frequency conversion and wavelength control to achieve the desired operating characteristics and should offer unprecedented levels of performance in this important wavelength regime.
The range of applications for this technology is enormous and goes well beyond gas sensing and pollution monitoring. Hence the results of this work are expected to open up many new avenues of research as well as new applications.
The project is supported by the European Commission under the Information Society Technologies priority of the Sixth Framework Program, and involves close collaboration with the Fibre Bragg Gratings and Silica Fibre Fabrication groups within the ORC, and with European partners, Thales Research and Technology (France), Norsk Elektro Optikk (Norway), University of Dusseldorf (Germany) and University of Valladolid (Spain). Further details can be found on the project web site at http://www.neo.no/village/.
Copyright University of Southampton 2006