Abstract

We recently reported remarkably large third- order nonlinear optical susceptibilities in a series of metal-substituted tetrakis-(cumylphenoxy)phthalocyanines¹ (MPcCP₄) at 1.064 μm, a wavelength far from resonance with the main absorption bands. The χ⁽³⁾ ranged up to 2 × 10⁻¹⁰ esu. The figures of merit χ⁽³⁾/ατ of these materials are also very large. The third- order susceptibility was enhanced by a factor of up to 50 by transition-metal substitution. The underlying mechanism responsible for the nonlinear response in these materials was not known. To elucidate the mechanism, the metal- free prototype, H₂PcCP₄, was studied in more detail.

© 1991 Optical Society of America