Reverse saturable absorption of porphyrin-like complexes

We report here the experimental observations on the nature of the reverse saturable absorption over the visible region(450470 nm) for two novel porphyrin - like complexes and tetraphenylporphyrin using open aperture z-scan. They all exist large reverse saturable absorption between the Soret and Q bands. A theoretical study has been carried out using 5-level models. The two novel samples have better optical limiting than tetraphenylporphyrin.