Third-order nonlinear optical properties of symmetric phenoxazinium chlorides with resonance structures at 532 nm

A series of symmetric phenoxazinium chlorides, which have good solubility in polar solvents and good thermal stability, were evaluated in acetonitrile solution for third-order nonlinear optical properties at 532 nm using nanosecond and picosecond Z-scan techniques. The title compounds exhibit strong reverse saturable absorption and nonlinear refraction. The third-order nonlinear optical properties under nanosecond laser beam irradiation and picosecond laser beam irradiation were obtained. The nonlinear mechanism is revealed as excited-state nonlinearity by a picosecond pump-probe response experiment for one of the compounds.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Strong reverse saturable absorption and nonlinear refraction under both nanosecond and picosecond laser beam. ► Excited-state nonlinear mechanism implied by pump-probe response. ► Good solubility in polar solvents and good thermal stability.