Physics Journal of the Indonesian Physical Society
GAIN CLAMPING IN L-BAND ERBIUM-DOPED FIBRE AMPLIFIER USING AN OPTICAL FEEDBACK
S.W. Harun, N. Tamchek, P. Poopalan and H. Ahmad
Department of Physics, University of Malaya
50603 Kuala Lumpur, Malaysia
Gain clamping in a long wavelength (L-band) erbium-doped fibre amplifier (EDFA) using an optical feedback is demonstrated, Various gain levels can be achieved by attenuating the feedback optical powers, which changes the optical cavity loss of the EDFA in ring cavity. The clamped gain level decreased from 18.9 dB to 14.2 dB, and the corresponding noise figure degraded from 4.3 dB to 6.5 dB for the input 1580 nm signal power of -30 dBm when the clamping-loop attenuation is varied from 16.5 dB to 0 dB. The increment of feedback power increases the saturation power with reduction in gain level. Therefore the degradation in noise figure is observed.