Theoretical and experimental study of multi - wavelength pumped photonic crystal fiber Raman amplifier
|Keywords||Stimulated Raman scattering (SRS) Photonic crystal fiber Fiber Raman amplifier (FRA) Gain flattened Simulated annealing algorithm Cladding-pump Erbium-Ytterbium co-doped|
All-optical amplifiers with large gain-bandwidth are required extensively because of the increasing of the capacity of optical fiber communication systems and the development of Wavelength Division Multiplexing (WDM) technologies. Fiber Raman Amplifiers (FRAs), which use the intrinsic nonlinear properties of transmission fibers to obtain signal amplification, are the most promising in broadband optical amplifiers owning its unique performances. Taking advantage of several intriguing and remarkable properties of the photonic crystal fibers (PCFs), such as high nonlinearity and controllable dispersion, the performance of photonic crystal fiber Raman amplifier in optical communication will greatly approved. Therefore, multi-wavelength pumped PCF Raman amplifier has been researched as the main subjects in this thesis. And the main contents are listed as follows:1. Multi-wavelength pumped PCF Raman amplifiers with gain flatness are theoretically investigated. A novel optimal design method for multi-pumped FRAs is presented. And a novel multi-wavelength PCF Raman amplifier is designed with four pumps and eight signals. The gain flatness for the multi-pumped micro-structured fiber Raman amplifier is less than 1dB within the bandwidths of 70nm.2. Experimental study on the pump technology of the Multi-wavelength pumped PCF Raman amplifier. A dual-wavelength cladding-pumped Erbium-Ytterbium co-doped fiber laser with tunable wavelength spacing is designed for the pump of the FRA. The two main parts of the pump, the TFL and the erbium-ytterbium co-doped double-cladding amplifier, are presented and tested. The TFL have a continuous wavelength tuning range of 40nm within 1530-1570nm, and its maximum and minimum power are 11.23dBm (13.27mW) and 10.87dBm (12.22mW), respectively, with a fluctuation in the tuning spectral range of less than 0.4dBm. The erbium-ytterbium co-doped double-cladding amplifier has a maximum saturated output power of 2.182W at around 1541nm. And the average gain achieves more than 20dB with gain flatness of less than 0.3dB, in a range of 40nm.