Thermooptical sound generation by Bessel light beams in gyrotropic low-dimensional structures

Thermooptic sound generation by Bessel light beam (BLB) in the naturally-gyrotropic two-layer superlattices for the case of registration of the resulting signal by gas-microphone cell method is investigated. It was found that the rate of energy dissipation of the TE-mode BLB essentially depends on the radial coordinate $\rho$, dissipative parameters of the superlattice $\varepsilon_1''$, $\varepsilon_2''$, the relative thinkness of the sample $x=d_1/D$ as well as BLB taper angle $\alpha$. It is shown that the change in the amplitude of the photoacoustic signal in gyrotropic superlattices is achieved through the formation TE- and TH-modes BLB by using axicon with an adjustable cone angle.