SUPPRESSING INTERFERENCE IN SPECTROSCOPIC SYSTEMS USING ABSORPTION MASKS

Abstract

This thesis represents an ongoing research project in which absorption masks were used toreduce scattering in a Herriott multipass cell in a Wavelength Modulation Spectroscopy (WMS) system. To that end, this thesis presents some of the following steps to success- fully see a scattering reduction in the absorption spectrum. It is organized in a few chap- ters and sets up a stage for the different methods implemented to tackle the scattering is- sue. This thesis, then, embarks on a discussion of the numerical method used for approxi- mation. A discussion of various techniques used to simulate and design masks follows. The implementation of the mask in the experimental system is also analyzed. Finally, this the- sis concludes with recommendations and the following steps to see a significant decrease in scattering in the optical cell.