Off-resonant third-order optical nonlinearities of metal-substituted phthalocyanines

Abstract
The third-order optical susceptibility of the Pt, Pb, and metal-free tetrakis(cumylphenoxy)phthalocyanines was measured by degenerate four-wave mixing at 1.064 μm, far from strong absorption bands. Metal substitution strongly enhances the off-resonant χ(3). The χ(3)xxxx for Pt-phthalocyanine (2×10−10 esu) and Pb phthalocyanine (2×10−11esu) is about 45 times and 5 times that of the metal-free form (4×10−12 esu), respectively.