Tuning the soliton-effect compression via stretching of the pump

Abstract

We investigate numerically the effect of introducing stretching-induced initial chirp on the soliton-effect pulse compression. We find both the positive and negative initial chirps can lead to improved compression, but through different mechanisms. With the positive initial chirp, the amount of stretching that yields the best achievable compression decreases for an increasing soliton number, whereas with the negative initial chirp, it increases. Moreover, we observe that the compression length can be substantially altered by stretching the pump, and it can even be shorter than that for the transform-limited pump within a small range of positive initial chirp. We note also, the stretching factor that gives the shortest pulse output extends the compression length by 1.23 times for any given soliton order. This study demonstrates that the soliton-effect compression can be readily controlled and optimised by placing a variable stretching element beforehand. It is useful especially in experimental setups where the length of the compressor cannot be readily modified.