ИСТИНА

The possibility of increasing the efficiency of acousto-optical diffraction at a wavelength of 10.6 μm due to the application of acoustoplasmic interaction is considered. The source of infrared radiation was a CO2 laser operating in a continuous mode. The surface plasmon-polariton at the metal boundary was excited by Otto's method using a germanium prism. The dependence of the reflection coefficient of the insulator-air-metal system as well as the dielectric-air-insulator system on the air gap, and also dielectric permittivities of layers was analytically obtained. The theory was developed for both TE and TM polarization. It was established that the reflection at the incidence angle of plasmon excitation in the case of TM polarization depends on the permittivity of the metal. In the case of TE polarization only narrow waveguide modes that are weakly dependent on the properties of the metal were observed. Experimental studies of the properties of the insulator-air-metal structure during modulation of the air gap by acoustic oscillations was carried out. An experimental setup for measuring the depth of modulation of the reflection coefficient at a wavelength of 10.6 μm has been developed. In the experiment a modulation depth of 25 ppm / nm was obtained.