Regulation of soliton inside microresonators with multiphoton absorption and free-carrier effects.

The influence of frequency detuning on the field in silicon microresonators with multiphoton absorption and FC effect is investigated. In this study, results show that frequency detuning facilitates soliton generation. With appropriate frequency detuning, not only bright solitons but also dark ones can be excited in silicon microresonators, which compensates for the absence of solitons with multiphoton absorption and FC. In particular, the larger the frequency detuning is, the wider is the combs spectrum with 2PA obtained. In order to excite the soliton efficiently, the regulation of frequency detuning with multiphoton absorption and FC effect is also studied. In regulating the frequency detuning process with 2PA, a progressively enhanced soliton can be formed in the region near zero detuning. In the tuning process, 3PA can generate bright and dark solitons respectively at various detuning intervals, and independent bright solitons can be observed in microresonators with 4PA. The research results are significant for studying the generation of solitons in silicon microresonators with multiphoton absorption and FC effect.