56.6 dB high gain L-band EDFA utilizing short-length highly-doped erbium rare-earth material

M H Al-Mansoori,W S Al-Ghaithi

doi:10.2971/jeos.2014.14028

Abstract

In this paper, we experimentally investigate the performance of an efficient high gain L-band erbium-doped fiber (EDF) amplifier structure utilizing short-length highly-doped erbium rare-earth material with a single pump source. The amplifier gain and noise figure variation for different amplifier structures have been investigated. A filter is used to reduce the self-saturation effect and suppress the C-band amplified spontaneous emission (ASE) noise. The amplifier achieves a signal gain of 56.6 dB with a low noise figure of 4.8 dB at −50 dBm input signal power using only 8 m of EDF length. The amplifier gain shows significant improvement of 6 dB with C/L band coupler and 13 dB with tunable-band pass filter compared to amplifier structure without ASE suppression.

Highlights

Erbium Doped Fiber Amplifiers (EDFAs) are one of the most efficient optical fiber amplifiers in the present and future development of all fiber-to-the home (FTTH) optical networks and long-haul dense wavelength division multiplexed (DWDM) optical communication systems [1]
Among the other gain enhancement techniques proposed is the use of a two stage structure with a bypass isolator [17] or in-line fiber Bragg grating (FBG) with forward-backward pumping scheme [18], a three-stage structure of erbium-doped fiber (EDF) pumped by 980 nm and 1480 nm laser diodes, which can achieve 35 dB gain with 5 dB noise figure [19] and the use of residual pump power in a three-stage configuration [20]−[21]
The main limitation to the performance of multistage L-band EDFA is imposed by amplified spontaneous emission (ASE) noise

Summary

INTRODUCTION

Erbium Doped Fiber Amplifiers (EDFAs) are one of the most efficient optical fiber amplifiers in the present and future development of all fiber-to-the home (FTTH) optical networks and long-haul dense wavelength division multiplexed (DWDM) optical communication systems [1]. The main limitation to the performance of multistage L-band EDFA is imposed by amplified spontaneous emission (ASE) noise These limitations can be overcome by incorporating optical filter within the amplifier to suppress the ASE. A flat gain bandwidth of 17 dB in two-stage L-band EDFA using pump distribution technique and 25 m of EDF length is demonstrated [22] Even though these approaches have enhanced the gain of Lband EDFA, the enhancement is at the expense of more than one pump source, longer EDF lengths and the high number of optical components used in the amplifier structure. The optimization of the pump powers, the input signal power and wavelengths and to the optical filter which suppress the amplified spontaneous emission noise

EXPERIMENTAL SETUP AND OPERATION PRINCIPLE

AND DISCUSSION

CONCLUSION