Planar waveguide circulating Gaussian beam resonators on a silicon photonic chip

Area of Science:

• Photonics
• Integrated Optics
• Materials Science

Background:

• Silicon photonics is crucial for integrated optical circuits.
• Conventional silicon ring resonators face limitations due to sidewall roughness and scattering losses.
• Developing robust and broadband silicon resonators is essential for advanced photonic applications.

Purpose of the Study:

• To design and characterize a novel silicon slab waveguide resonator.
• To evaluate its performance in all-pass and add-drop configurations.
• To compare its advantages over traditional silicon ring resonators.

Main Methods:

• A silicon slab waveguide resonator with a folded two-dimensional Gaussian cavity was designed.
• Light coupling was achieved using beam splitters formed by narrow gaps.
• Resonance line widths and Q-values were measured for a 100 μm path length cavity.

Main Results:

• Measured resonance line widths of 5 pm and Q-values of 310000 were achieved.
• The resonator demonstrated a comb of resonance lines over a 100 nm tuning range.
• The design showed broadband operation and reduced susceptibility to scattering losses.

Conclusions:

• The proposed silicon slab waveguide resonator design enables broadband operation.
• It offers improved performance compared to silicon ring resonators, particularly regarding sidewall roughness.
• This design is promising for next-generation integrated photonic devices.