Internship Report from the year 2017 in the subject Physics - Experimental Physics, grade: 2,0, University of Bayreuth (Physikalisches Institut), course: Physikalisches Praktikum für Fortgeschrittene, language: English, abstract: Lasers are very commonly used in everyday life, e.g. in laser pointers, CD-Players or the lasers used in cash registers. But what makes lasers special and distinguishes them from other light sources? Which advantages do they have and what are their applications in physics? In the experiment "Laser" in the Advanced Physical Practicum the task is to find out which mathematic coherences there are between parameters of the laser and to test how good they match the experimental observation.