A Versatile Laser-Based Experimental Setup for the Chemistry and Physics Curricula

Washington And Lee University, Lexington VA

Investigators

Abstract

Chemistry (12) The Departments of Chemistry and Physics are actively pursuing curricular reform and modernization of their teaching laboratories. The goal of this project is the introduction of a versatile Nd:YAG-pumped dye laser system and supporting equipment into three courses: a capstone course to the general chemistry sequence that is designed to develop fundamental concepts introduced briefly in this sequence (e.g., atomic structure), a modern physics course available to students in their sophomore year who have completed the introductory sequence, and a new, two-term modern physical chemistry lab course that will complement the associated lecture. The laser's versatility, robustness, and attractiveness to students make it ideally suited to serve as the cornerstone apparatus for a focused series of experiments. These experiments allow students to develop an intuitive understanding of difficult, fundamental concepts that are at the heart of chemistry and physics. Portions of many of the proposed experiments are adapted from established experiments from the educational or research literature. Representative examples include the photoelectric effect, laser induced fluorescence, transient emission spectroscopy for fast kinetics measurement, and high resolution atomic and molecular absorption spectroscopy using multi-photon and cavity ring-down laser absorption spectroscopy (CRLAS). Introduction of the simple, powerful absorption technique, CRLAS, into the undergraduate curriculum is a novel element of this project and requires the adaption of experiments from the research literature. Finally, because students are exposed to the laser and data acquisition during their first year, they are well prepared early in their college careers to participate in an active research program that applies the laser to studies of gas phase photochemistry and reaction dynamics. In addition, students in advanced courses have the opportunity to propose and develop new experiments that are pedagogically relevant and whose results will be disseminated both at conferences and in the chemical literature.