Non linear optical (NLO) polymers have great potential to be fabricated into integrated electro-optic (E/O) devices for use as high speed electro-optic (E/O) switches, modulators and interconnects in computer and communication systems [1,2]. The fabrication of practical integrated E/O devices requires a material system that meets the final device requirements and can be processed using standard fabrication technologies . Applications of polymer E/O devices in electronic systems have been limited by the relatively low thermal stability and poor processability of non linear optical (NLO) polymers. This paper describes a thermally stable electro-optic material system and the fabrication process to make compact integrated E/O devices for application in electronic systems. This material system consists of high thermal stability polyimide core and cladding materials. The active NLO material is a side chain polyimide that uses a new high activity and high thermal stability chromophore.