Photonic ICs await their utilisation

The future of InP integration technology, in the face of developments towards hybrid optical assembly and of success with polymers and 'silica-on-silicon' technology, is questioned. In the opinion of many experts, only through use of photonic integrated circuits can the necessary decisive thrust in cost reduction for photonic modules and systems be achieved. This technology offers a broad potential for innovation with regard to components having new functionalities. Examples are depicted of a WDM transmitter, a bidirectional optical transceiver, a polarisation diversity heterodyne receiver, a tapered-lightguide-to-glass- fibre optical field matching transformer and an 'optical motherboard'.