Integrated optic devices for coherent transmission

The components required for coherent optical-fiber systems are discussed, and those devices that can be implemented using electrooptic waveguide technology are identified. The current usage of integrated optic components in coherent optical-fiber systems is indicated, and the system performance that has been obtained when these components are employed is summarized. The design and performance of LiNbO3 electrooptic waveguide modulators, optical combiners, frequency translators, and polarization controllers are reviewed, and the benefits to be gained by employing optical-integrated circuits in coherent optical-fiber systems considered. Finally, a novel low-voltage LiNbO3 optical-integrated circuit for use in coherent detection is presented and the various design compromises discussed.