A mode-locked fibre laser system for multi-point intra-cavity gas spectroscopy

We have described a new way of realising a multi-point, multi-gas sensor system based on a mode-locked fibre laser with potential application for trace gas detection in environmental and safety monitoring. Although based specifically on erbium-fibre lasers, the principles could be extended to other laser types, for example, Tm/sup 3+/ fiber lasers in silica glass or the use of semiconductor optical amplifiers which are commercially available for the 1300-1600 nm region, extending the range of gas sensors possible. Preliminary experiments have been conducted to test the principles and research is currently in progress to demonstrate a fully multiplexed system.