Progress towards a 1300 nm fibre amplifier

Abstract

Optical fibre amplifiers are key devices for increasing the transmission distance, speed and capacity of optical communication systems. We report on current worldwide progress in the development of glass fibre amplifiers for amplification in the 1.3 micron transmission window. There are three candidates for a practical device for this application, all of which require a glass host which is not silica based. As a consequence, performance and application of these devices does not yet match that of the erbium doped fibre amplifier operating at 1.55 microns. However, the majority of land-based optical fibre operates at wavelengths around 1300 nm therefore there remains considerable interest for a practical amplifier. Recent trends, such as the development of wavelength-division multiplexing (WDM) systems, has meant that fibre amplifiers must meet a variety of requirements. These include high gain, high output power, a low noise figure, a broad and flat gain spectrum, high reliability, low cost, and compactness. Candidates for a 1.3 micron fibre amplifier include praseodymium doped fluoride (PDFA) or a similar device based on chalcogenide glasses, both of which have demonstrated amplification though not yet at practical levels; neodymium doped fluoride glasses for which signal gain is possible but severely limited by competing transitions; and dysprosium doped chalcogenide glasses, from which only fluorescent has been demonstrated. In this presentation we review progress in these three variations of the ubiquitous 1300 nm optical fibre amplifier