Integrated Optics for Optical Communications

Abstract

The present status of fibre optical communication can briefly be characterized by: - high data rate, long distance transmission in the 1.3–1.6 µm wavelength region with single-mode fibres; - the penetration of single-mode fibre links into subscriber loops and local area networks; - the growing interest in coherent detection systems. This evolution of fibre optical technology with its emphasis on single mode fibres and sophisticated systems has stimulated again the interest in integrated optic devices for optical communication. Integrated Optics, which is essentially a single-mode technology, is expected to contribute to cost-effective, high bandwidth switches/modulators, to multiplexing, filtering, and signal routing devices. The monolithic electro-optical integration using the InGaAsP-material system is thoroughly investigated. At present, however, integrated optic devices on LiNbO₃ have achieved a higher status of development with respect to technology, device performance, and fibre coupling.