Optical fiber devices

摘要

Optical fibers are used extensively for the transmission of information and have largely replaced copper circuits for all but the shortest distances. They are capable of enormous bandwidth, very low transmission loss and minimal error rates. However whilst a range of passive fiber components is available to help exploit the fiber capability, much of the signal processing is still carried out electrically. This repetitive transformation from the optical to the electrical domains and back is obviously clumsy and inefficient. Fortunately active fiber devices also exist and the range of these is steadily increasing thus reducing the need for electrical intervention in optical systems. A new technology of integrated fiber circuits is emerging.