Some features of acousto-optical methods as applied to measurement technology

Abstract

Some features of acousto-optical methods as applied to measurement technology are considered. The intensity of diffraction maxima are modulated at light beam diameter comparable to the acoustic wavelength. Such phenomena take place for light beam diffraction at surface ultrasonic waves (Rayleigh waves), capillary waves on a surface of a fluid as well. The signal modulation frequencies depend not only on the wave frequency, but also on the studied medium velocity. Signal modulation phases depend on wavelength. Therefore such methods may be useful for various problems of measurement technology, as the optical scheme of the measuring device can be very simple: laser -- medium under study (in which one of the indicated waves is excited) -- photodetector.