The application of optical sensor systems in a harsh industrial environment calls for small and rugged optical components. The emerging availability of integrated. optical circuits for distribution, modulation or switching of the sensing light beam may lead to the necessary miniaturization and mechanical stability of the system. The integrated optis technology in combination with fiber optic sensors increases the possibility of advanCed architectures for potentially low cost devices when mass produced. An overview is given with concern to some design criteria, materials and fabrication principles for waveguiding structures for integrated optical sensors.