Silicon multi-mode micro-ring modulator for improved robustness to optical nonlinearity.

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Silicon micro-ring modulators are crucial for optical communications but suffer from performance degradation due to optical nonlinearity at high input power.
• The resonant nature of micro-rings amplifies nonlinear effects, limiting device performance.

Purpose of the Study:

• To propose and experimentally demonstrate a novel multi-mode silicon micro-ring modulator.
• To mitigate the impact of optical nonlinear effects in silicon micro-ring modulators by operating in a higher-order mode.

Main Methods:

• Developed a multi-mode silicon micro-ring modulator design.
• Experimentally operated the modulator in the TE1 mode.
• Characterized the modulator's performance under varying input optical power, focusing on resonance spectrum shape and wavelength shift.

Main Results:

• The TE1 mode demonstrated a higher nonlinear threshold compared to the TE0 mode due to increased waveguide loss and effective mode area.
• Under 10 mW optical input power, the resonance spectrum maintained a symmetric Lorentz shape.
• The resonant wavelength shift was less than one resonance linewidth, indicating improved robustness.

Conclusions:

• The multi-mode silicon micro-ring modulator operating in the TE1 mode effectively mitigates optical nonlinear effects.
• This approach offers improved robustness against high input optical power compared to conventional silicon micro-ring modulators.
• The findings pave the way for higher-performance silicon photonic devices.