Noise reduction in long-haul lightwave all-amplifier systems

Author

Habbab, Isam M I ; Saleh, Adel A M ; Frigo, Nicholas J. ; Bodeep, George E.

Author_Institution

AT&T Bell Lab., Holmdel, NJ, USA

Volume

10

Issue

9

fYear

1992

fDate

9/1/1992 12:00:00 AM

Firstpage

1281

Lastpage

1289

Abstract

The overall gain of a chain of erbium-doped fiber amplifiers in a long-haul all-amplifier system would be automatically stabilized if each amplifier were operated slightly into saturation. However, with the required low level of amplifier output power which is imposed by nonlinearity in the transmission fiber, the resulting pump power becomes too low to effectively invert the gain medium of the amplifiers. Consequently, the amplifier output noise level becomes too high for proper system operation. This problem is solved by pumping the amplifiers harder so that a higher gain and higher output power are achieved. The excess gain is then counteracted by an appropriate value of post-amplifier loss. Because of the higher pump power in this case, the amplifier noise is reduced significantly. This technique is investigated theoretically, and experimental work that verifies it is reported

Keywords

erbium; fibre lasers; noise; optical communication equipment; optical solitons; Er-doped fibre amplifiers; NRZ system; gain; long-haul lightwave all-amplifier systems; noise reduction; output noise level; output power; post-amplifier loss; pump power; soliton system; Erbium-doped fiber amplifier; High power amplifiers; Noise figure; Noise reduction; Optical amplifiers; Optical fiber amplifiers; Optical noise; Power amplifiers; Power generation; Semiconductor optical amplifiers;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/50.156880

Filename

156880