Fluoride-based erbium-doped fiber amplifier with inherently flat gain spectrum

We successfully developed a fluoride-based Er3+-doped fiber amplifier (F-EDFA). An average signal gain of 26 dB was achieved for 8 channel wavelength division multiplexed (WDM) signals in the 1532-1560 nm wavelength region with a gain excursion of less than 1.5 dB at an input signal power of -20 dBm per channel, Furthermore, we studied the amplification characteristics of the F-EDFA for WDM I signals, The following experimental results were obtained, 1) For an g-channel WDM signal in the 1532 to 1560 nm wavelength region, the gain excursion between channels can be suppressed to within 1.5 dB. However, the wavelength region allowing a gain excursion of 1.5 dB, is between 1536-1560 nm for the silica-based Er3+-doped fiber amplifier, 2) F-EDFA's have a flat gain region between 1534-1542 nm. The gain excursion of this region is less than 0.2 dB for WDM signals.