This article describes the synthesis and second-order nonlinearity study of several new polyphosphazene polymers, which are composed of a new type of nonlinear optical chromophore attached to polyphosphazene. They were obtained via a post-azo coupling reaction. The resulting materials were characterized with H-1-NMR, P-31-NMR, Fourier transform infrared, ultraviolet-visible, gel permeation chromatography, and differential scanning calorimetry. Chromophore contents up to 14 mol % were realized. The polymers had good optical transparency, and poled films revealed resonant d(33) values in the range of 18-37 pm/V by second harmonic generation measurements. (C) 2008 Wiley Periodicals, Inc.