The purpose of this manual is to help students learn to solve problems in the course of optics on the topic of ''Diphration''. The analysis and solution of the most typical examples, analytical and graphic methods of solution are considered in detail. Proposed tasks for independent work. The textbook was prepared at the Department of General Physics of the Faculty of Physics of Voronezh State University . Recommended for students of 2 full-time courses and 3 full-time courses in the specialty: 010701 (010400) - 'Physics', 010801 (013800) - 'Radiophysics and electronics', 010803 (014100) - 'Microelectronics and semiconductor devices'