Picture of two heads

Open Access research that challenges the mind...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs. Strathprints provides access to thousands of Open Access research papers by University of Strathclyde researchers, including those from the School of Psychological Sciences & Health - but also papers by researchers based within the Faculties of Science, Engineering, Humanities & Social Sciences, and from the Strathclyde Business School.

Discover more...

Suppression of intensity modulation contributions to signals in second harmonic wavelength modulation spectroscopy

Chakraborty, Arup Lal and Ruxton, Keith C. and Johnstone, W. (2010) Suppression of intensity modulation contributions to signals in second harmonic wavelength modulation spectroscopy. Optics Letters, 35 (14). pp. 2400-2402. ISSN 0146-9592

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

Abstract

Recovery of the full 2f wavelength modulation spectroscopy (WMS) signal in isolation from the 2f residual amplitude modulation (RAM) due to nonlinear intensity modulation (IM) and distortion due to linear IM is demonstrated. The 2f RAM is eliminated using a fiber delay line, while the linear IM-induced distortion is eliminated by a phasor decomposition approach. This generic and robust two-pronged strategy removes the need to separately measure the 2f RAM in high-modulation-index calibration-free 2f WMS. It is also important for widely tunable 2f WMS using nontelecom diode lasers with highly nonlinear characteristics leading to high-2f RAM levels.