Reverse saturable absorption of lanthanide bisphthalocyanines and their application for optical switches

We have investigated reverse saturable absorption (RSA) of tetrakis(2,9,16,23-tert-butyllanthanide bisphthalocyanines)(M(TBPc)(2), M = Lu, Dy, Tb) with Z-scan technique. Furthermore, lanthanide bisphthalocyanines have also been utilized for optical switches based on their RSA performance. However, the experimental results reveal that the performances of RSA and optical switches for M(TBPc)(2) (M = Lu, Dy, Tb) are poorer than that of tetrakis(2,9,16,23-tert-butylcopper phthalocyanines) (Cu(TBPc)) due to strong intramolecular pi-pi interaction between the two Pc rings. (C) 2004 Elsevier B.V. All rights reserved.