Coherent coupling of ultrashort temporal cavity solitons revealed via real-time spectroscopy

Bound-states of temporal solitons − termed “Soliton molecules” or “Soliton crystals” – are observed in microcavities and ultrafast resonators. Recently, we introduced high-speed spectroscopy to resolve the formation and control of such states in mode-locked Ti:sapphire oscillators by employing real-time spectral interferometry [1,2]. In this contribution, we resolve a novel mechanism mediating short-range soliton bound-states based on real-time measurements and by introducing a refined analysis of relative soliton phases. We corroborate our findings with a numerical interaction model for the coherent soliton coupling and discuss prospects for future schemes of high-speed intra-cavity spectroscopy.