Efficient modeling of resonant electro-optic phase modulator dynamics through a mean-field equation

Area of Science:

• Photonics
• Optical Engineering
• Nonlinear Optics

Background:

• Resonant electro-optic (REO) phase modulators in high-Q ring resonators offer a compact method for generating high-repetition-rate optical frequency combs.
• Efficient modeling of these systems is complicated by factors like dispersion and radio-frequency (RF) detuning.

Purpose of the Study:

• To derive a computationally efficient model for REO phase modulators in ring resonators.
• To accurately capture the effects of dispersion, optical detuning, and off-resonant RF modulation on comb generation.

Main Methods:

• Derivation of coupled-mode equations for a dynamically modulated ring cavity.
• Development of a spatiotemporal mean-field equation incorporating dispersion and detuning.
• Efficient computation of the steady-state comb spectrum using a tridiagonal linear system.

Main Results:

• The derived model accurately reproduces time-domain simulations with significant computational speedup.
• A closed-form estimate for the dispersion-limited comb bandwidth was obtained.
• The model effectively handles arbitrary-order dispersion, optical detuning, and off-resonant RF modulation.

Conclusions:

• The new modeling approach provides a substantial computational advantage for simulating REO phase modulators.
• This method enables accurate prediction of optical frequency comb generation, including dispersion effects.
• The findings facilitate the design and optimization of compact frequency comb sources.