Bidirectional initiation of dissipative solitons in photonic molecules

Dissipative solitons (DSs) can be generated in microresonators featuring Kerr nonlinearities via continuous wave (CW) pumping, forming a frequency comb in the spectral domain. While single cavity DSs have been thoroughly investigated in the last years, recent efforts have moved towards photonic molecules (linearly coupled cavities). These arrangements give rise to exotic physical phenomena and practical improvements in terms of conversion efficiency and tuneable comb dynamics. In a recent study of normal dispersion photonic molecules, we found that DSs can be generated in absence of intracavity CW bistability. Here, we show that this feature enables the CW initiation of DSs, tuning the laser into resonance either from the blue side or the red side. While DS initation from the red side has been demonstrated with the photorefractive effect, this is the first demonstration of bidirectional initiation that only requires a Kerr nonlinear medium