Optics and Optical Design - The Optical Path Length of a Vacuum-Spaced Fabry-Perot Interferometer

Answer to a viewer's question about finding the optical path length difference between two interfering rays in a Fabry-Perot interferometer. I changed the title of this video by replacing "air-spaced" with "vacuum-spaced" since the analysis was done using a refractive index of exactly 1. Please consider clicking on "LIKE". I don't get paid for creating this content, and your positive feedback is the only encouragement that I receive to continue creating this kind of helpful material.