Reverse saturable absorption of a novel rhodamine-B cation fulleride salt at 532 nm

A novel rhodamine-B cation fulleride salt was synthesized by metathetical r eaction. Its tetrahydrofuran solution was prepared and the fluence-dependen t transmission was measured with 10-ns 532-nm laser pulses in a collimated optical setup. With increases in the input fluence, its transmittance decre ased significantly, which indicated reverse saturable absorption behavior. For comparison, the input fluence-dependent transmittance of fullerene C-60 and rhodamine-B solution were also measured. The nonlinear optical limitin g effect of the fulleride salt in tetrahydrofuran is slightly lower than th at of C-60 in toluene and the explanations are provided.