Third-order optical nonlinearities of a processable main chain polymer with symmetrically substituted tris-azo dyes

Abstract
A new third‐order nonlinear optical (NLO) polymericmaterial for all‐optical waveguidedevices is designed, which is a main chain polymer with symmetrically donor‐substituted NLO units as part of the polymer backbone. On the basis of the molecular design, the polymer has large third‐order NLO susceptibility, χ(3), potentially low propagation loss and high processability for channel waveguide fabrication. The magnitude of χ(3)(−3ω;ω,ω,ω) for the polymer film was 1.5×10−10 esu at the three‐photon resonant wavelength. This is the largest value for highly processable polymers.