Picture of DNA strand

Pioneering chemical biology & medicinal chemistry through Open Access research...

Strathprints makes available scholarly Open Access content by researchers in the Department of Pure & Applied Chemistry, based within the Faculty of Science.

Research here spans a wide range of topics from analytical chemistry to materials science, and from biological chemistry to theoretical chemistry. The specific work in chemical biology and medicinal chemistry, as an example, encompasses pioneering techniques in synthesis, bioinformatics, nucleic acid chemistry, amino acid chemistry, heterocyclic chemistry, biophysical chemistry and NMR spectroscopy.

Explore the Open Access research of the Department of Pure & Applied Chemistry. Or explore all of Strathclyde's Open Access research...

Recovery of absolute absorption line shapes in tunable diode laser spectroscopy using external amplitude modulation with balanced detection

Bain, James R. P. and Lengden, Michael and Stewart, George and Johnstone, Walter (2016) Recovery of absolute absorption line shapes in tunable diode laser spectroscopy using external amplitude modulation with balanced detection. IEEE Sensors Journal, 16 (3). pp. 675-680. ISSN 1530-437X

[img]
Preview
Text (Bain-etal-Sensors-2015-Recovery-of-absolute-absorption-line-shapes-in-tunable-diode-laser-spectroscopy-using-external-amplitude)
Bain_etal_Sensors_2015_Recovery_of_absolute_absorption_line_shapes_in_tunable_diode_laser_spectroscopy_using_external_amplitude.pdf
Accepted Author Manuscript

Download (343kB) | Preview

Abstract

Accurate recovery of an absorption lineshape is important in many industrial applications for simultaneous measurement of gas concentration and pressure or temperature. Here we demonstrate a method, based on a modification to the Hobbs balanced receiver circuit, for background signal nulling when external amplitude modulation of the laser output is used. Compared with direct or non-nulled detection techniques, we demonstrate that the method significantly improves the signal to noise ratio to a level comparable to that of conventional second harmonic wavelength modulation spectroscopy. Most importantly, normalisation and recovery of the lineshape is straightforward and immune to the difficulties that afflict lineshape recovery with conventional wavelength modulation spectroscopy.