Innovative triazine-core octupolar chromophores: unlocking new Frontiers in nonlinear optics

The nonlinear optical (NLO) properties of differently structured organic materials, such as low-weight dyes, macromolecular chains, or those functionalized by metal ions, have been widely investigated and are crucial for various applications in fields such as photonics, optical sensing, and data transmission. In this study, we explore the use of a 1,3,5-triazine core for constructing new azo/stilbene-based octupolar NLO chromophores (NLOPhores) and investigate their linear, second-order, and third-order NLO properties. Specifically, we examine their all-optical switching, causing remote optical anisotropy of the refractive index through the global re-ordering of photochromic molecules in host-guest polymeric thin films using the Optical Kerr effect. Additionally, NLOPhores were analyzed experimentally using the Z-scan methodology, as well as the comparative techniques defining the second and third harmonics of light generation (SHG and THG). These comprehensive studies demonstrate the significant potential of azo/stilbene-based octupolar chromophores with an embedded 1,3,5-triazine core in optoelectronics and quantum optics applications. Molecular motions within functionalized octupolar NLO chromophore, with photosensitive chains comprising dual-constructed azo/stilbene units. All-optical switching is initiated by linearly polarized UV light and monitored using red-light laser line.