Fresnel's biprism - Experiment

In this experiment the students have to determine the wavelength λ of the laser using two-beam interference through a biprism according to Fresnel. This experiment is one of the methods developed by Augustin Jean Fresnel, along with the double mirror experiment, to generate 2 coherent light beams and bring them to interference. Even though the two experimental setups differ slightly from each other, the basic geometric relationships are the same in both experiments. Because of this, the further tasks of the two experiments are chosen differently. While the double mirror experiment addresses the topic of coherence, the prism angle is to be determined following the measurements with the Fresnel biprism.