Nonlinear absorption spectrum of ytterbium bis-phthalocyanine solution measured by white-light continuum Z-scan technique

In this work we have measured the nonlinear absorption spectrum of ytterbium bis-phthalocyanine (YbPc2) in chloroform solution employing the Z-scan technique with white-light continuum (WLC) pulses. Two distinct excited state absorption behaviors were observed: a saturable absorption (SA) at the Q-band region and a reverse saturable absorption (RSA) around 530 nm. A three-energy-level diagram was used to explain the experimental results, leading to the excited state absorption cross-section determination from 500 up to 675 nm.