In order to suppress transient excursion of output signal,a novel scheme to modify the edge waveform of pulse signal is proposed,and transient response to a signal with slowly changed leading-edge is investigated,which is based on the finite-difference algorithm to simulate four-level rate-propagation equations of new-type broad-band tellurite-based erbium-doped fiber amplifier (EDTFA).

As we know, the intrinsic gain spectrum characteristics of broadband tellurite-based fiber amplifier (EDTFA) is not flat, so we designed a kind of dual-stage structure with a gain equalization filter between fibers.

Based on the rate equations and light propagation equations of four energy level system, the performances of gain and noise figure of broadband erbium-doped tellurite fiber amplifier(EDTFA) with an isolator in the midway are researched.

Gain characteristics of a erbium-doped tellurite glass fiber applied for broadband amplification;