Spectral dependence of the anisotropy of χ(3) of epitaxially grown vanadyl phthalocyanine film

A study on the spectral dependence of the anisotropy of χ(3) of epitaxially grown vanadyl phthalocyanine has been performed using the technique of third-harmonic generation. It is found that the variation in the anisotropy of χ(3) is a result of the dispersion of the complex ratio 3χ1221/χ1111. There is a sharp two-photon resonance in the χ(3) spectrum which is 1.88 eV above the ground state. Enhancement of χ(3) is achieved in the unidirectionally oriented vanadyl phthalocyanine film by one order of magnitude.