Polymer devices and high bandwidth optoelectronics

Certain speciality polymers have the dual properties of low dielectric constant and large electro-optic coefficients. This is the reason for great interest in seeing their implementation as electron-optic devices in high bandwidth systems. The origin of the electro-optic response in these materials, their composition and physical properties is discussed in the context of the application areas targeted. Special attention is focussed on devices for integrated optics. In this regard, methods of forming low loss optical waveguides by, for example, spatially selective polar alignment and forming topographic features are critically assessed. Finally, the results of recent work demonstrate a polymeric integrated optical Mach Zehnder interferometer which addresses some of the requirements of a commercial specification. A method whereby inverted ribs etched in a polymeric lower cladding layer controls the mode size is described. Using a low guide-to-cladding index difference mode sizes compatible with fibre modes have been achieved. A moderate extinction ratio in monomode TM operation is shown and the prospects for demonstrating low drive power are reflected in high electro-optic coefficients (~40 pm/V) seen in planar guides