Optics and Optical Design - The Fabry-Perot Interferometer: What Do the Fringes Mean?

So, you are doing your pre-lab due diligence for a Fabry-Perot experiment. You're not alone if you don't see a straight line between the descriptive mathematics and the fringes. I did some soft experiments to help me to recognize the meaning of the fringes. There are a lot of variables to control in a real experiment and running simulations can be so helpful because you can know and control the extraneous factors. That's what's going on in this video. Enjoy! Typo at 7:00 - There should be a factor of t-squared multiplying the ratio of cosines. At 7:20 the next line appears correctly with a factor of t-squared multiplying each cosine ratio. The simulations described in this video were done using Zemax OpticStudio (www.zemax.com). As a bonus, at the end I give a "hand-wave-free" explanation of why it is okay to ignore the phase shift the light experiences upon reflection. If you really don't need the theoretical background of the Fabry-Perot interferometer (Part 1), you can skip ahead to 9:14 (Part 2) where the soft experimentation using MATLAB and Zemax begins. Please consider clicking on "Like" so that I know what sort of content is being appreciated. I don't ask for support for developing this content, and your likes are the only encouragement that I get to continue making content like this. References 1. B.E.A Saleh and M.C. Teich, Fundamentals of Photonics; Part I: Optics, 3rd ed. (Wiley, 2019), Section 11.1 2. Pedrotti, Pedrotti, and Pedrotti, Introduction to Optics, 3rd ed. (Prentice-Hall, 2007), Section 8-4 3. Eugene Hecht, Optics, 4th ed. (Addison Wesley, 2002), Section 9.6.1