M. Cai et al., STUDY ON NOISE CHARACTERISTIC OF GAIN-CLAMPED ERBIUM-DOPED FIBER-RINGLASING AMPLIFIER, IEEE photonics technology letters, 9(8), 1997, pp. 1093-1095
A simplified method to estimate the noise figure of the optically gain
-clamped erbium-doped fiber amplifiers (EDFA's) is proposed, The simul
ation results indicate that the population inversion level at the sign
al input end dominates the noise performance of the entire amplifier,
For a gain-clamped EDFA with ring-lasing configuration, the effects on
the noise figure of the amplifier by the distributions of the pumping
and lasing powers as well as the lasing wavelength are analyzed theor
etically. The suggested noise-optimum configuration is co-pumping and
co-traveling lasing oscillation at 1531 nm. Near quantum limit interna
l noise figure of 3.6 dB is achieved in the experiments under the best
arrangement, The experiment results show perfect accordance with the
theoretical analysis.