This module is comprised of two separate submodules: (a) Michelson Interferometer and (b) Fabry-Perot Etalon. In the former light from a monochromatic point source is incident upon the interferometer. The user can vary the wavelength of the incident light, the position of the translation mirror, the tilt of the tilt mirror, and the position and size of the observation screen. In the latter monochromatic light from a point source is incident upon a slab of material of index of refraction 'n' and thickness 't'. The two sides of the slab are coated, each has the same reflectance 'R'. A finite cone of rays from the point source is allowed to strike the slab, and the slab is surrounded by air. The user is allowed to vary 'n', 't', 'R', and the wavelength of the incident light.