Direct visualization of terahertz electromagnetic waves in classic experimental geometries

Abstract

We used newly developed experimental methods to collect educational video clips of electromagnetic waves propagating at the speed of light. The terahertz frequency waves were generated and detected in LiNbO3 crystals structured to reproduce classic optical geometries and experiments, such as two-slit interference and diffraction from a grating. Direct visualization of the phase fronts as the electromagnetic pulses propagate, reflect, diffract, and interfere helps develop intuition and understanding about the fundamental behavior of light and waves. We believe these videos will be a valuable addition to lectures on introductory optics and physics, because they bring contemporary research to the classroom and provide clear and direct experimental demonstrations of light and wave behavior.