Investigation of tetrabenzporphyrin by the Z-scan technique

The nonlinear transmission of tetrabenzporphyrin dissolved in tetrahydrofuran was measured with the Z-scan technique at 532 nm with nanosecond pulses. The excited-state absorption cross section, the excited-state refractive-index cross section, and the linear and nonlinear absorption contributing to a thermal index change have been determined. To our knowledge, the excited-state cross section and its effective ratio to the ground-state cross section are the largest values reported to date.