Broadband and gain-flattened erbium-doped fiber amplifier for l-band amplification

摘要

The erbium-doped fiber amplifier (EDEA) is a key device for high capacity wavelength division multiplexing (WDM) optical communication systems. High density WDM transmission system using an EDEA requires more multiplexed channels. Therefore researches to expand an amplification bandwidth towards a longer wavelength side, so-called L-band, has been investigated. We have demonstrated a gain-flattened EDEA which has two stage amplification units connected by an optical isolator. The first unit is forward-pumped by 1.48 μm LD and the second one is backward-pumped by 1.48 μm LD. When the input power is -10 dBm and a product of Er concentration and erbium-doped fiber(EDE) length of each EDEA unit are 8 kppm· m and 100 kppm· m, 1-dB gain band from 1560 to 1606 um was achieved. Signal output power of more than +20 dBm was obtained in a wavelength range from 1560 to 1607 nm. With regard to power conversion efficiency, 50 ～ 60 % was obtained in the wavelength range within 1 -dB gain bandwidth. We also measured a four channel amplification characteristics. When the signal wavelengths are 1570, 1580, 1590 and 1600 nm and signal power is - 16 dBm per channel, output power of each channel were 15.9,15.9,16.6 and 15.7dBm and their deviation was ±0.45 dB.