Flat Gain Spectrum Design Of Multi-pumped Raman Fiber Amplifiers Based On Differential Evolution Optimization

With the developing of communication technology and the coming of the big data age, the bandwidth demand of consumers exponentially increasing. The emergence of wavelength division multiplexing (WDM) technology effectively alleviate the pressure of telecom operators. Therefore, as the key devies of WDM, optical fiber amplifier gradually got the attention of the researchers. Multi-pumped Raman fiber amplifier with low signal-to-noise ratio, good compatibility, high gain, flat gain spectrum and the wide gain bandwidth gradually become the hotspot in the field of optical fiber communication.This paper focuses the research of flat gain spectrum based on the multi-pumped Raman fiber amplifier. We start from the principle of Raman fiber amplifier, adopt Bumki simplified model, and then introduce some common methods of solving the model, such as the runge-kutta method, the average power and shooting method. After establishing the mathematical model and algorithm, this paper uses differential evolution algorithm to optimize input parameters(pump wavelength and power) of multi-pumped Raman fiber amplifier model, then achieve optimal output of the model. For this propose, a large number of simulation experiments are carried out. Firstly, to verify the effectiveness of the algorithm, differential evolution algorithm is applied to solve the optimization problem of pumped Raman amplifier; Secondly, The impact of pump number on the performance of the algorithm is analyzed. Results show that the more pump numbers, the more flat gain spectrum of the signal light at the same circumstances; Finally, experiment compares the performance of differential evolution algorithm with genetic algorithm and simulated annealing algorithm in multi-pumped Raman fiber amplifier optimization problem, and results show that differential evolution algorithm performs better.