In this paper,we first introduce the basic operating principle of Thulium-Doped Fiber Amplifier(TDFA) and Gain-Shifted TDFA(GS-TDFA) and analyze different pumping wavelength options.

Design of EDFA gain flattening filter using cascaded M-Z interferometer;

Study on noise figure and gain of EDFA;

A Wideband Amplifier Combining FRA with EDFA;

Gain and noise figure improvement of the reflection L-band erbium-doped fiber amplifier;

A novel Erbium-doped fiber amplifier(EDFA) pumped by 980 nm LD that improves the L-band amplification performances is demonstrated.

In the power telecom networks, the distance between two nodes is always too long to use the normal optical transceiver, so we have to use Erbium-Doped Fiber Amplifier (EDFA) additionally.

Numerical simulations show that, unlike conventional erbium-doped fiber amplifiers in which nonlinear effects lead to serious distortion of amplified pulses, the proposed device performs not only distortion-free amplification but also efficient compression of ultrashort solitons.

For comparison, we also simulated the performance of soliton system using erbium-doped fiber amplifiers (EDFAs) as in-line amplifiers.

The basic principle and characters of the erbium-doped fiber amplifiers are introduced, and their applications and recent advances in the wavelength division multiplexing and optical soliton transmission systems are summarized.