A new disubstituted polyacetylene with indolylazo moieties in its side chains (9) was synthesized by a post functionalization strategy, which was difficult, or perhaps impossible, to obtain from the direct polymerization of its corresponding monomer. The polymer is soluble in common solvents and thermally stable. The polymer shows good optical transparency with an absorption maximum at 393 mn and a band edge at similar to 530 nm. Its poled film exhibits a resonant d(33) value of 17.9 pm/V and its optical nonlinearity is resistant to thermal decay at up to 147 degrees C. (c) 2006 Wiley Periodicals, Inc.