Abstract: Double resonance spectroscopy is a technique whereby two lasers (i.e., two-color) are used to excite two real and different atomic transitions in a species of interest. The first step of the excitation process is the absorption of photons by the atomic species to the first excited state from the ground state. This is subsequently followed by a secondary absorption of photons from the first excited state to the second excited state. Once the atomic species have reached the second excited state, there are several methods for monitoring the events that occur, among these are ionization and fluorescence measurements. In the present study, three different measurement methods are used with three different atomization cells. The measurements demonstrate the usefulness of double resonance excitation processes as a diagnostic tool for flames, plasmas, and possibly, graphite furnaces, as well as an analytical method for the measurement of lead at femtogram levels in a graphite tube atomizer. Dissertation Discovery Company and University of Florida are dedicated to making scholarly works more discoverable and accessible throughout the world. This dissertation, "Double Resonance Spectroscopy as a Diagnostic Tool and Analytical Technique for Atomic Spectroscopy" by Moi Bon Leong, was obtained from University of Florida and is being sold with permission from the author. A digital copy of this work may also be found in the university's institutional repository, IR@UF. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation.