Competition between the excited-state refraction and excited-state absorption induced transient thermal refraction of metallic porphyrin compound

Abstract

The competition between the excited-state absorption induced transient thermal refraction and the excited-state refraction of a novel metallic porphyrin compound Zn-porphyrin was studied by the excited-state absorption induced transient thermal refraction theory combined with the excited-state refraction theory. The transformation between self-focusing and self-defocusing of the sample for different pulse widths was observed. The sample exhibited self-focusing effect attributed mainly to excited-state refraction for 4 ns laser pulse, while in the self-defocusing effect for 8 ns laser pulse the excited-state absorption induced transient thermal refraction dominates the excited-state refraction.