Information properties of acousto-optic tunable filters

摘要

Each acousto-optic device is intended generally for the purposes of information transmission and processing. Different kinds of such devices, however, transmit different kinds of information. Output information originating from acousto-optic tunable filters (AOTF) is contained in output light spectrum or wavelength. Amount of the transmitted informaiton depends on different factors; the most important among them are AOTF resolving power by wavelength and the processing rate. The resolving power can be defined according to the following criterion: two adjacent wavelengths are beforehand (usually determined by the customer of the device). This possibility can be measured if the valley between two peaks corresponding these wavelength is in the certain relationship with the value of noise. Hence, signal-to-noise ratio appears to be the most importnat factor describing informaiton posibilties of AOTF. From the othr hand, the processing rate depends on the temporal aperture of Bragg cell on the basis of whcih the device have bene designed. The calculations of the possible amount of informaiton to be transmitted by AOTF has been carried out both for collinear and non-collinear configurations of the device. The influence of features of slow shear acoustic wave propagation in tellurium dioxide single crystal in AOTF on informaiton transmission through AOTF has been considered and discussed.