Gain-equalized, eight-wavelength WDM optical add-drop multiplexer with an 8-dB dynamic range

The performance of a gain-equalized, eight-wavelength WDM optical add-drop multiplexer (W-ADM) has been measured. By operating the EDFA 9-dB into saturation, the gain was equalized to within 1 dB with a minimum gain of 15 dB, over a 20-nm optical bandwidth and for total input signal power variations of 8 dB. The individual output powers were constant to within 1 dB over a 6-dB range of input powers. These results indicate that for a large range of input signal powers it would not be necessary to readjust the EDFA gain equalizer. However, pump power degradation had a stronger impact on gain variation: a 1.4-dB reduction of pump power caused gain variations of 1.8 dB. In addition, polarization-dependent losses of the W-ADM induced output power fluctuations of 1.6 dB.<
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