Transformation of the microwave resonance properties of metastructures with cds and cdse at one- and two-photon excitation

Photonically controlled metastructures containing resonant conducting dipole and chiral elements with CdS and CdSe in gaps have been proposed, implemented, and studied in a waveguide and a meta-interferometer in the range of $3$–$12$ GHz. It has been found experimentally for the first time that the variation of the optical radiation power $P_\lambda$ guided by the optical fiber to the region of the discontinuity when the photon energy $h\nu$ is both above the width of the band gap $E_g$ $[h\nu(\lambda_1=0.53\,\mu$m$)>E_g]$ and below it $[h\nu(\lambda_2=0.97\,\mu$m$)<E_g]$ results in the transformation of the resonant response of the corresponding element (smooth variation of the intensity almost to the transparency level accompanied by a decrease in the frequency) in the microwave transmission spectrum, as well as in the transformation of the stopband in the interferogram of the meta-interferometer with a severalfold change in the width. In addition, under $\lambda_2$ irradiation, orange–red luminescence identified as a manifestation of anti-Stokes luminescence is observed on the CdS surface. Direct cavity measurements of the complex permittivity $\varepsilon^{\text{GHz}}$ of the CdS and CdSe samples have demonstrated an increase in both Im$\varepsilon^{\text{GHz}}$ (with approaching saturation at $\lambda_2$) and Re$\varepsilon^{\text{GHz}}$ with increasing $P_\lambda$. Characteristics of the identical manifestation of physical effects at microwave frequencies under one- and two-photon excitation have been revealed in application to the light energy flux densities $S_1$ (at $P_{\lambda_1}$) and $S_2$ (at $P_{\lambda2}$): $S_2\gg S_1$; $S_2^2/S_1 = \text{constant}$.