Acousto-Optical Spectroanalyzer on Azimuthally Inhomogeneous Bessel Light Beams

The main characteristics of an acousto-optic spectrum analyzer with spatial integration based on Bessel light beams in paratellurite crystals are investigated. The diffraction efficiency was investigated and expression for one was derived, that depends from the parameters of o- and e-type Bessel beams, and from overlap integrals values and the frequency detuning of the Bragg synchronism. The absence of exact transverse phase matching of diffracted Bessel light beams leads to the frequency resolution of the acousto-optic spectrum analyzer is ~ 3.5 kHz. It is found that the upper limit of the dynamic range of the spectrum analysis is proportional to the square of the overlap integral of the diffracted Bessel light beams. It is shown that with an increase in the mode order of the Bessel light beam, the type of the amplitude-frequency characteristic of the device does not change in the presence and absence of transverse synchronism of the diffracted light beams of zero and first order.