ИСТИНА

The dependence of the linear and nonlinear optical properties of silicon nanowires (SiNWs) on their structural properties was investigated. SiNWs with diameter between 40 and 200 nm were grown on crystalline silicon (c-Si) substrates by metal-assisted chemical etching and had a strong scattering of light in the visible and infrared spectral range. Nonmonotonic dependence of the total reflectance of light from SiNWs on their length was discovered. It was found that the indicatrix of the elastic scattering of light with a wavelength of 1064 nm in the SiNW ensembles longer than 2 μm can be approximated by the Lambert's cosine law and the intensity of the scattered light in the rear hemisphere grows logarithmically with increasing the length of SiNWs. It was found that in SiNWs the efficiency of frequency conversion of optical radiation, such as Raman scattering, coherent anti-Stokes Raman scattering and third-harmonic generation, were increased compared to c-Si substrates. Cross-correlation functions of photons scattered in SiNW arrays were measured for the first time and it was found that the interaction of light with SiNWs was multiple times increased compared to c-Si substrates. Nonmonotonic dependence of the intensity of the interband photoluminescence in the range of 1100-1200 nm from SiNWs on their length was found for the first time. The reported study was funded by RFBR according to the research project No. 14-02-31544 мол_a.