Experimental Research On Erbium-Doped Fiber Amplifier And Development Of Its Driver

Nowadays erbium-doped fiber amplifier(EDFA) is one of the key devices of DWDM system. Whether is its performance good or not will directly influence the performance of the system. This dissertation is focused on some pivotal techniques of EDFA and its driver as follows: 1. The development of EDFA's driver Two drivers of 980nm laser diode(LD) are achieved with analog circuit. For simplifying circuit design, strengthening control and optimizing display interface, other drivers are also achieved with digital circuit, one for 980nm LD and the other for 1480nm LD. The performance of all products accord with the design desire. 2. Experimental research on the broadband EDFA Based on the respective research of C band and L band EDFA, C+L band broadband EDFA is carried out with the assemble scheme of parallel structure. With using cascade fiber loop mirror(FLM), flat gain is obtained. Broadband gain of the amplifier above 30dB is achieved with 3dB gain bandwidth of 57nm including 25nm(1530nm～1555nm) in C band and 32nm(1570nm～1602nm) in L band. 3. Experimental research on the optical automatic gain clamping(OAGC) EDFA Single and dual wavelength OAGC experiments are operated with loop cavity scheme. The method of using the FLM in the feedback loop as filter is proposed for the first time to realize the dual-wavelength clamping. 0.1dB gain ripple is obtained as the result of the validity of this method. For low noise, cascade structure is adopted. As a result, noise figure is less than 8.15dB with the input signal Pin<-15dBm. 4. Experimental research on novel bismuth-based EDF We give the first report on the experimental studies of bismuth-based EDFA and broadband super-fluorescent source(SFS). The bandwidth of gain above 10dB is about 70nm(1540nm～1610nm) under different input conditions. And the bidirectional-pump, double-pass structure SFS based on the novel type EDF demonstrates the 88nm line-width with the output power of 14.3dBm.