Time-domain simulations of nonlinear interaction in microring resonators using finite-difference and coupled mode...

Area of Science:

• Silicon photonics
• Nonlinear optics
• Optical microcavities

Background:

• Microring resonant cavities are key for on-chip nonlinear optics.
• Frequency combs in microrings have significant scientific and practical potential.
• Understanding nonlinear comb formation mechanisms requires advanced simulation.

Purpose of the Study:

• To develop a computationally efficient simulation method for nonlinear microring dynamics.
• To accurately model frequency comb formation in silicon photonic devices.
• To explore novel comb generation mechanisms and pulse shaping.

Main Methods:

• A hybrid approach combining linear finite-difference time domain (FDTD) simulations with coupled-mode theory.
• Utilizing FDTD for key interaction parameters and coupled-mode theory for nonlinear dynamics.
• Validating the hybrid method against full FDTD simulations.

Main Results:

• The hybrid method accurately reproduces results from full FDTD simulations in both frequency and time domains.
• Comb formation is demonstrated to be possible with both anomalous and normal dispersion.
• A new mechanism for incoherent (Type II) frequency comb formation is proposed.
• A method for generating soliton-like pulses in microresonators is illustrated.

Conclusions:

• The hybrid simulation technique offers a faster and more stable alternative to full FDTD for nonlinear microring analysis.
• This method facilitates the exploration of diverse nonlinear phenomena in silicon photonic devices.
• The findings advance the understanding and design of on-chip frequency combs and optical solitons.