Several high-performance polymeric electro-optic modulators have been demonstrated in the last decade. Most of them have been elaborated using specific high-performance electro-optic polymers designed for their exceptional electro-optic response and their thermal stability. In this paper we report the high performance of electro-optic modulators made of a commercial side-chain electro-optic copolymer DR1-PMMA as the active core material and of a passive epoxy polymer NOA73 as cladding material. The electro-optic polymer used in these modulators is a Disperse Red 1- poly-methylmethacrylate (DR1-MMA) side-chain copolymer with relative molar concentrations of DR1-substituted (resp. MMA unsubstituted) groups equal to 30% (resp. 70%). We have designed, elaborated and tested phase modulator and pushpull Mach-Zehnder modulators in order to optimize their figure of merit VπL. A push-pull Mach-Zehnder modulator with 2 cm-long electrodes and an inter-electrode distance of 8.8 μm displays a half-wave voltage of 2.6 V at 1550 nm, corresponding to a figure of merit of 5.2 V.cm. This result was obtained with a moderate poling electric field of 75 V/μm applied to the core of the modulator waveguide. We report here the best figure of merit which has never been observed in a modulator realized with a commercial side-chain electro-optic polymer.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.