ИСТИНА

Homogeneous metallic films are widely used in optoacoustics as optical energy to sound transducers. Increase in efficiency may be achieved by reducing the reflection coefficient of the transducer film. The simplest method is to use instead of a film a one-dimensional metal lattice having plasmon resonance. The presence of plasmon resonance leads to a significant increase in the absorption coefficient, which ensures an increase in conversion efficiency. However, of interest is the creation of a converter with a non-uniform conversion factor. For example, this may be of useful in problems of generation of acoustic vortex pulses by the optoacoustic methods. In our report, we discuss the results of investigating transducers based on plasmonic nanoparticles with a linearly varying in the azimuthal angle of the density of the arrangement of these particles on the surface. Depending on the concentration of nanoparticles, a different optical absorption coefficient will be observed. Earlier it was shown that the creation of such a distribution of the absorption coefficient will ensure the possibility of forming acoustic pulses with an inhomogeneous phase and amplitude profile. Calculations of the dynamics of elastic deformations will make it possible to construct a theoretical model for the formation and propagation of an acoustic vortex in a medium.