Perform Fresnel's Biprism Experiment on a 1m optical bench. Precision optics allow fringe position measurements to 1/100mm. Easy alignment and adjustment of the two virtual light sources. Fresnel's Biprism Experiment is the fundamental example of common path interference by division of wavefront. Light from a slit passes through side-by-side prisms with very shallow angles to separate it into two almost parallel beams. When these beams are brought to overlapping by a convex lens, they interact as if they originated from two virtual sources side by side and generate equally-spaced fringes. The original version of the experiment by Fresnel is difficult to perform because it requires precise adjustment of the slit and prisms, a dark room, and a large amount of space to separate the fringes for easy viewing. This product has a 90 day lead time. Market standard for this type of product.