An Introductory Undergraduate Experiment on Second Harmonic Generation

Abstract

This project is part of a comprehensive revision of the Undergraduate Physics Laboratory Curriculum at the University of Waterloo, supported by the Dean's Undergraduate Teaching Initiative, Waterloo Science Endowment Fund (WatSEF), and the Sinclair Foundation. I have designed an introductory-level experiment on Second Harmonic Generation (SHG). SHG is a nonlinear optical process in which photons interact to produce light at twice their original frequency. The experiment is taught using inquiry-based instruction. Students investigate whether SHG depends on pulse energy, peak power, or laser intensity using a Titanium Sapphire femtosecond laser (850±50nm, 100±50fs pulses) and a Beta Barium Borate (BBO) crystal. The experiment will be implemented in the new Gee-Whiz Lab Course (GWLC), where students will conduct contemporary physics experiments without requiring prior subject mastery. This approach encourages students to revisit these beyond-introductory-level topics throughout their undergraduate education and explore how experimental investigations contribute to progress in physics in ways distinct from theoretical approaches. Preliminary work suggests the experiment is both technically feasible and pedagogically effective, providing a foundation for future introductory-level curriculum development in nonlinear optics and other topics typically reserved for upper-year or graduate study.