Direct visualization of terahertz electromagnetic waves in classic experimental geometries

Direct visualization of terahertz electromagnetic waves in classic experimental geometries. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. 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 LiNbO 3 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.