Nonlinear optical properties of highly oriented polydiacetylene evaporated films

Abstract
Third‐order harmonic generation has been measured on highly oriented polydiacetylene (PDA) films prepared by the vacuum deposition method. Experimental values of the third‐order electric susceptibility χ(3) measured for pumping laser polarized parallel to the polymer chain show a sharp three‐photon resonance to the 1Bu exciton in PDA. Potential usefulness of these highly oriented PDA evaporated films in nonlinear optical applications is suggested.