Picture of smart phone in human hand

World leading smartphone and mobile technology research at Strathclyde...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by University of Strathclyde researchers, including by Strathclyde researchers from the Department of Computer & Information Sciences involved in researching exciting new applications for mobile and smartphone technology. But the transformative application of mobile technologies is also the focus of research within disciplines as diverse as Electronic & Electrical Engineering, Marketing, Human Resource Management and Biomedical Enginering, among others.

Explore Strathclyde's Open Access research on smartphone technology now...

Recent advance in tunable diode laser spectroscopy with background RAM nulling for industrial applications

Ruxton, K.C. and Chakraborty, A. and McGettrick, A.J. and Duffin, K. and Stewart, G. (2009) Recent advance in tunable diode laser spectroscopy with background RAM nulling for industrial applications. In: 20th International Conference on Optical Fibre Sensors, 2009-10-05.

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

Abstract

A limiting factor of tuneable diode laser spectroscopy (TDLS) with wavelength modulation spectroscopy (WMS) is the presence of background residual amplitude modulation (RAM) on the recovered 1st harmonic signal. The presence of this background term is due to direct modulation of the source laser power. This work presents a novel method to optically remove the unwanted background, with the major benefit being that measurement sensitivity can be increased. The recently developed phasor decomposition method1 (PDM), is a near IR (NIR) TDLS analysis technique that is used with the addition of the new RAM nulling method to recover gas absorption line-shapes. The PDM is a calibration free approach, which recovers the gas absorption line-shape and the isolated 1st derivative of the line-shape from the 1st harmonic signal. The work presented illustrates and validates the new RAM nulling procedure with measurements examining the 1650.96nm absorption line of methane (CH4) with comparisons to theory.