A photoaddressable azobenzene-side-chain polymer (see Figure) optimized to exhibit a large optical birefringence of Deltan = 0.5 at 650 urn is described. The birefringence extends well into the telecommunication wavelength region, which, together with the high optical transparency above 650 nm, promises applications for integrated photonic device applications. The writing dynamics of the polymer are examined, and it is shown that the rewriteability is limited by photobleaching.