Research On Broadband EDFA And Gain Control

WDM/DWDM (Wavelength Division Multiplexing/Dense WDM) has already broadened the bandwidth of communication system, and become the highlight of exploitation and application. At the same time, there appears some further demand to the EDFA as the development of WDM/DWDM, such as the broad bandwidth, automatic gain control and automatic power control.According to the project of super-broadband fiber amplifier and intelligent fiber amplifier and resource, this dissertation focuses on the study of the broadband, the flatness and gain control of EDFA. The main contents are listed as follows.1.The integrated discuss of the development in EDFA gain control technology, including gain flattening and gain clamping techniques has been introduced. A series of typical schemes are compared and discussed. Several experiment schemes are presented.2. We have demonstrated a novel VOA based on high birefringence fiber loop mirror, which has many advantageous characteristics such as a simple structure, high flexibility, polarization independence, low insertion loss and low price, etc. Experimental proof shows that it is convenient to realize the control of optical power by using this VOA .3.A wavelength-tunable erbium-doped fiber laser by using FBG and HiBi fiber loop mirror as reflectors is presented. A series of lasers with about 0.8nm spacing have been achieved. The SMSR is higher than 54dB. A dynamic range of over 13.5dB of the output laser intensity has been realized by tuning the reflectivity of fiber loop mirror with polarization controller.4.A novel structure L-band erbium-doped fiber ring laser is demonstrated, which has much improved the performance of L-band fiber ring laser. To be recycled, the backward ASE was routed to the input of EDF by an optical circulator. This method is much use for reference to enhance the gain of L-EDFA in broadband link.5. A flat high efficiency super-broadband source was presented. We achieved a C+L-band super- fluorescent source, in the region from 1520 to 1600.4nm, the power of the ASE are over -25.0dBm and the ASE profile excursion is only±1.4dB in the region from 1527.2 to 1603.2nm.6. A novel structure L-band erbium-doped fiber amplifier by using HiBi fiber loop mirror as...