Abstract

Optical amplifiers for use in fiber communications systems have been a reality for some years now. However, the inherent linearity, low crosstalk, low noise, high efficiency, polarization insensitivity, and low insertion and coupling losses of the erbium-doped silica fiber amplifier (EDFA) has made this the favored device for 1.55-µm telecommunications. Indeed, the use of optical amplifiers in the 1.3-µm window has been to some extent bypassed by the success of the EDFA for 1.55 µm. Despite the development of multiquantum well (MQW) semiconductor amplifiers giving high gain and low polarization sensitivity at 1.3 µm, the nonlinearity and crosstalk performance have ruled out their widespread use for multichannel telecommunications. In addition, the relative pump inefficiency of Raman amplifiers has precluded their widespread acceptance as communications amplifiers. The question of whether an equivalent of the EDFA for 1.3 µm exists still remains; this paper explores that question.

© 1992 Optical Society of America