Thermal stability enhancement of electrooptic polymer modulator

We synthesized a novel electrooptic (EO) polymer with good thermal stability and high optical nonlinearity. The EO polymer has a side-chain structure of a hyper-branched chromophore in polyetherimide. In order to improve the thermal stability, the EO polymer has been designed to have a high glass transition temperature (178/spl deg/C). The hyper-branched chromophores induced a large EO coefficient (35 pm/V at 1550 nm). An optical intensity modulator based on the EO polymer was demonstrated. The measured half-wave voltage was 8.5 V and the extinction ratio was 18 dB. The modulator showed good thermal stability at 125/spl deg/C.