Ability-based design and applications of TiO2-, SiO2- mesostructured hybrid sol-gel films in nonlinear photonics

G. Telbiz1, S. Bugaychuk2, V.Gulbinas3
1L.V. Pisarzhevsky Institute of Physical Chemstry, NAS of Ukraine, Prospect Nauki 31, Kyiv, Ukraine, 03128
2Institute of Physics, NAS of Ukraine, Prospect Nauki 46, Kyiv, Ukraine, 03028
3Center for Physical Sciences and Technology, Savanoriu 231, Vilnius, Lithuania. 

The elaboration of new hybrid materials is sparked widespread interest in the photonics community [1]. Besides feature an effected good  performance for linear light-matter interactions, these materials also exhibit extraordinary nonlinear optical properties. One of the earliest demonstrated examples is the possibility of the ultrafast response of Si Ti hybrid films [2, 3]. Today, the range of nonlinear phenomena that explored in also includes nonlinear THz interactions, wave mixing processes, self-focusing effects, and several others. Furthermore, the various combination of 2D materials with photonic integrated circuits and nanostructures, providing both tight light confinement/enhancement and the possibility of modulating the materials’ properties through doping has great promise for using in the integrated optics devices. Depending on the preparation technology of these materials, the mesoscopic films can be formed as porous dielectric material with surface of different thickness, roughness and contain the guest dye molecules confined with high fluorescent properties [3]. The thickness of the films varies from 160 nm up to 600 nm and index refraction 1.3-1.8. The structural properties of these films have studied using XRS, FTIR, SEM, AFM methods, fluorescence, optical linear and nonlinear properties. Early was shown that hybrid TiO2 ans SiO2 film works as a genuine waveguide on good quality guided modes. Both types of waveguide operate in the main single mode. The measurements confirm that the lasing threshold for the genuine waveguide is about two orders lower than for the hollow one [4]. Our latest researches is the study of ultrafast nonlinear optical response in such films induced by femtosecond laser pulses.

[1] G. Telbiz, S. Bugaychuk, E. Leonenko, and all, Nanoscale Research Letters, 10:196, P.1-7 (2015).
[2] S. Bugaychuk, A. Iljin, G. Telbiz, and all , Journal of Molecular Liquids, 267, 34-37 (2018).
[3]  A. Kazakevičius, D. Peckus,  L. Valkunas,  E. Leonenko, G. Telbiz and V. Gulbinas. Journal of Phys.Chem. C, 119, 19126−19133, (2015).
[4] E. A. Tikhonov, V. P. Yashchuk and G. M. Telbiz, Laser Phys. 28, 045801-1-7, (2018)