Picture of UK Houses of Parliament

Leading national thinking on politics, government & public policy through Open Access research

Strathprints makes available scholarly Open Access content by researchers in the School of Government & Public Policy, based within the Faculty of Humanities & Social Sciences.

Research here is 1st in Scotland for research intensity and spans a wide range of domains. The Department of Politics demonstrates expertise in understanding parties, elections and public opinion, with additional emphases on political economy, institutions and international relations. This international angle is reflected in the European Policies Research Centre (EPRC) which conducts comparative research on public policy. Meanwhile, the Centre for Energy Policy provides independent expertise on energy, working across multidisciplinary groups to shape policy for a low carbon economy.

Explore the Open Access research of the School of Government & Public Policy. Or explore all of Strathclyde's Open Access research...

A novel fiber-optic intra-cavity sensing network using a mode-locked fiber ring laser

Yu, H.D. and Jin, W. and Liao, Y. and Stewart, G. and Culshaw, B. and Ho, H. and Li, Y. (2002) A novel fiber-optic intra-cavity sensing network using a mode-locked fiber ring laser. In: 15th Optical Fiber Sensors Conference, 2002-05-06 - 2002-05-10.

Full text not available in this repository.Request a copy from the Strathclyde author


A promising method for high sensitivity gas detection is intra-cavity spectroscopy [l] where the gas absorber is placed directly within a laser cavity. The high sensitivity arises from the very large number of passes through the gas cell within the cavity, effectively transforming a short absorption cell into a highly efficient multi-pass system. As a consequence a weak gas absorption line can have an enormous impact on the laser output. Recently intra-cavity spectroscopy with fiber lasers has attracted considerable attention [2,3,4]. An all-fiber intra-cavity laser system can use the mature passive and active fiber components from the communications market with compact micro-optic gas cells, allowing safe, remote and continuous gas monitoring. Additionally, fiber laser sources have a broad gain bandwidth, such as the erbium-fiber laser with gain over 1530-1580nm, and thus can be used as a source for a multi-gas sensor avoiding the cost of individual (DFB) lasers for each gas. However the high cost of the active fiber components such as the Erbium-Doped Fibre Amplifier (EDFA) would also limit the commercial application of single point measurements with intra-cavity fiber spectroscopy. Ideally an intra-cavity system would be capable of making multi-point measurement of several gases within the gain spectrum of the erbium doped fibre laser. A multiplexed network would greatly reduce the cost per point by sharing the same fiber source and the same signal-processing unit. In this paper, we present a system that combines a mode-locked fiber ring laser with intra-cavity spectroscopy to distinguish between different gas cells in a ladder sensing network. The system outputs strong pulsed lasing signals only when certain matching conditions are satisfied [5] and individual sensors are addressed by different frequencies of the mode-locked fiber ring laser.