Basic principles, Fourier analysis, 2D-Fourier transformation, Fourier spectroscopy, correlation measurement techniques, fiber sensors, thin film measurement systems, Bragg Sensors, Sagnac sensors. The lecture presents basics of the theory of modern optical measurements and their realisation. It comprises four parts: Fourier Transform, Infrared Spectroscopy, Correlation Techniques and Optical Fibers. The first part presents one and two dimensional Fourier Transform as the way of describing of an optical pattern. Influences of optical components on the transmitted signal are explained. The second part of the lecture takes up with the problems of infrared spectroscopy as a method of quick substance identification. Construction and performance of an infrared spectrometer are explained. In the part devoted to the methods of signal correlation its application to optical sensing systems such as optical Radar are explained. At last theory of light propagation in optical fibers and an overview of fiber-sensors are presented.