Multi-photon properties of branched chromophores derived from indenoquinoxaline and oxadiazole heterocyclic units

Two chromophoric congeners derived from indenoquinoxaline and oxadiazole are designed, synthesized and characterized for their multi-photon properties in the femtosecond time domain. These two model structures are experimentally found to exhibit strong and widely distributed two- and three-photon activities within the spectral range of 680-1500 nm and the larger congener manifests maximum two- and three-photon absorption cross-section values of 2120 GM (at 750 nm) and ∼85 × 10⁻⁸⁰cm⁶s²(at 1280 nm), respectively. Both two- and three-photon absorption-based optical power-limiting performance of a representative model compound are also evaluated and demonstrated.