Real-time transition dynamics of harmonic mode-locking states with spectral filtering effect in a hybrid mode-locked fiber laser

We experimentally investigated the transition dynamics between 2nd and 3rd harmonic mode-locking states using the dispersive Fourier transform technology in a hybrid mode-locked fiber laser. Keeping the pump power unchanged and adjusting polarization controller to change intracavity-loss-dependent gain profile and the spectral filtering effect, a set of soliton dynamics induced by soliton interaction are revealed before the soliton splitting. Solitons undergo similar oscillation behaviors during the reverse decay process of the harmonic mode-locking order until one of the solitons disappears. In these transient dynamics, a significant wavelength shift phenomenon could be observed in the transition process of harmonic orders. The numerical results further show that intracavity spectral filtering effects play key role in the harmonic order transition dynamics process, consistent with experimental results. It provides new insights into the evolution and dynamics behavior in harmonic mode-locked soliton order conversion and its potential applications.

Automated summary

This study experimentally investigates the transition dynamics between 2nd and 3rd harmonic mode-locking states in a hybrid mode-locked fiber laser using dispersive Fourier transform technology. By adjusting the intracavity-loss-dependent gain profile and spectral filtering effect, induced soliton dynamics are observed before soliton splitting. During the reverse decay process of harmonic mode-locking order, solitons exhibit similar oscillation behaviors until one of them disappears. A significant wavelength shift phenomenon is observed in the transition process of harmonic orders. The numerical results and experimental findings both demonstrate the important role of intracavity spectral filtering effects in the harmonic order transition dynamics process.