toc1955's video: Homemade Fabry Perot interferometer

(Adolf Cortel, october 2012). [ After recording this video I have greatly improved the performane of the apparatus. If interested in Fabry-Perot interferometers, have a look at https://www.youtube.com/watch?v=Aqftqp29aWE ] More improvements in my homemade Fabry-Perot interferometer. The mirrors are pieces of (commercial) optical window polished at 1/10 th of wavelength, silvered by sputtering (about 55 nm of silver thickness). The parallelism of the mirrors is critical and "long" rods inserted in the adjustment screws simplify a lot the delicate task. The apparatus resolves very well the doublet of sodium, as shown in the video