Z-scan study of nonlinear absorption in novel lanthanide bis-phthalocyanines

► Nonlinear absorption of novel lanthanide bis-phthalocyanines BuPc2Ln was studied. ► All compounds exhibit reverse saturable absorption at 532 nm excitation. ► RSA was studied with the open aperture z-scan technique. ► Numerical modeling based on the rate-equations formalism was conducted. ► RSA is due to the strong triplet state absorption.