Study Of Fiber Raman Amplifier Theory And Implementation Techniques

DWDM technique and optical amplifier are two milestones in fiber communication field. DWDM has enabled an explosive increase in the capacity of optical transmission systems with announced commercial systems now reaching capacities beyond 1 Tb/s. To obtain even higher capacity, it will be necessary to increase the spectral efficiency of these C- and L-band systems or utilize wavelength bands outside the erbium window. Fiber Raman Amplifier (FRA) based on SRS effect in the transmission fiber to obtain amplification enable the capacity of future high-capacity systems to be increased using both those approaches. Raman amplification, distributed Raman amplifiers and hybrid Raman/EDFA are considered.Raman amplification offers the prospect of high gain, high saturation power and polarization insensitivity in a fiber device, combined with a smooth gain spectrum and relatively wide bandwidth. These properties are ideal for use as a signal amplifier in high speed, WDM transmission systems. FRAs are being deployed in almost every new long-haul and ultralong-haul fiber-optic transmission systems, making them one of the first widely commercialized nonlinear optical devices in telecommunications. The contents of this dissertation is an important work base on the national 863 plan. It systemically analyses principles and theoretics design of FRA. And the test results are given detailed. The main research contents and results are given as follows:The basic theory of Raman scattering and the characteristics of stimulated Raman scattering in fiber are detailed. Characteristics including gain property, noise property, polarization correlation and temperature stability of FRA are discussed, The key techniques are mentioned.Starting with the FRA configuration, the paper dissertates the designing process of C+L band FRA and the drive and refrigeration circuit of pump source. A monitor and control system on FRA is developed. The design method of the hardware and the flow of the monitor program is demonstrated based on the key parameters of FRA. Optimized methods of design of broadband flat-gain FRA are stated .According to the national 863 plan's acceptance criterion and IEC-61290, A test scheme is studied out. All test results are set out detailed, comparing with congener products.The last chapter also summarize the principle, configuration and characteristics of hybrid Raman/Erbium-Doped Fiber Amplifiers(HFA), introducing the fundamental configurations and experimental results of four types of HFA.