Date of Award

2016

Document Type

Open Access Thesis

Department

Chemistry and Biochemistry

Sub-Department

College of Arts and Sciences

First Advisor

S. Michael Angel

Abstract

The need to development lightweight miniature sensors for spectrometers for use in hazardous environments such as war zones, industrial settings, and space exploration is ever growing. This thesis will present studies aimed at improving Raman instruments for such applications by reducing the size, weight, and power consumption of the instrument. The two methods described here include the utilization of a light emitting diode (LED) source for Raman spectroscopy and a new type of Raman gas sensor.

Chapter one describes a new Raman spectrometer that utilizes an LED for Raman excitation coupled to the SHRS. LEDs are highly divergent broadband , extended light sources that are not typically suitable for Raman measurements. In this work a broadband LED is optically filtered and the light is focused onto various solid and liquid samples where the large field of view of the SHRS is fully utilized to collect a large fraction of the Raman scattered light. The coupling of the SHRS with LED excitation shows great promise for the full utilization of LED excitation and provides great potential for spectrometer miniaturization and reduction of instrument size, weight, and power consumption.

Chapter two describes two new Raman gas cells. The first method couples a multi-pass capillary cell (MCC) to the newly developed spatial heterodyne Raman spectrometer (SHRS). The SHRS’s large field of view allows for directly coupling the MCC to the spectrometer without a fiber optic while maintaining a signal to noise ratio equivalent to the results recorded using fiber optically coupled MCC devices. The second method involves new hollow waveguide (HWG) designs, and a new gas chamber coupled to a dispersive Raman spectrometer with a new type of fiber optic Raman probe.

Rights

© 2016, William Joshua Huntington

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