Correlation of solitons in bidirectional mode-locked fibre laser

The experimental investigation of formation of coherent structures from noise is essential for fundamental understanding of nonlinear systems. Here, we present switch-on dynamics in bidirectional mode-locked laser in spatio-temporal and frequency domains by using Dispersive Fourier Transform for both clockwise and counter-clockwise directions. We have calculated cross-correlation of counter-propagating beams that reveals the dissimilarities between formation of the spectra of counter-propagating pulses. From cross-correlation we revealed periodic patterns which manifest complex exchange dynamics between the counter-propagating pulses at different stages of their mutual formation. These results will help to understand complex soliton dynamics and nonlinear systems in general.