Novel method for cascaded Raman fiber lasers

As for the numerical solution of cascaded Raman fiber laser(CRFL) optical power coupling equations, the problem is that the conventional shooting algorithm is a waste of time and easily undershoots. In the new algorithm the equations is simply transformed to obtain the fitness function which can be solved by the optimization algorithm. According to the actual situation of fitness function, the improved particle swarm optimization(PSO) can enhance the optimization capability of complex functions compared with the basic PSO. The algorithm is also tested by the fitness functions derived from the theoretical model of different structures of CRFLs, and the calculating time is no more than 15 s when the accuracy of the fitness function is 10-5. The algorithm used in conjunction with the Newton-R