Design and fabrication of high-performance Er3+-doped fiber devices

Abstract

Optimization of both fiber and device design is essential for maximum performance from erbium doped optical fibers as either line, pre- or power amplifiers, with optimum fiber composition and geometry being unique for each application. The field is extensive but selected examples are reviewed to indicate the range of device configurations and fiber structure available. Key advances include, via fiber design the development of ultra high gain efficiency for reduced pump power requirements and hence increased reliability of practical systems. Further, use of a novel device configuration allows exploitation of high gain efficiencies without compromising noise levels for a pre- or line amplifier. Power amplifiers demonstrating high output powers even at elevated signal levels are sought for many communications systems including local area networks. Both amplifier configuration and fiber composition have been investigated in the pursuit of output signals in excess of 20 dBm. The relative merits of these systems are discussed and future direction indicated. In summary, it is shown that optical fiber fabrication plays a key role in optimizing performance while the versatility of fiber circuitry allows full exploitation of the fiber potential.