Negative coupling and coupling phase dispersion in a silicon quadrupole micro-racetrack resonator

Area of Science:

• Photonics and optical engineering
• Solid-state physics
• Materials science

Background:

• Micro-racetrack resonators are key components in integrated photonics.
• Understanding coupling mechanisms is crucial for device performance.
• Dispersion effects in coupled systems require further investigation.

Purpose of the Study:

• To experimentally investigate the impact of coupling phase dispersion on the spectral response of a two-dimensionally coupled quadrupole micro-racetrack resonator.
• To analyze the manifestation of negative coupling in the system's spectral characteristics.
• To demonstrate the potential for advanced silicon photonic devices utilizing complex coupling coefficients.

Main Methods:

• Fabrication and characterization of a two-dimensionally coupled quadrupole micro-racetrack resonator.
• Experimental measurement of the spectral response under varying coupling conditions.
• Analysis of the filter response, focusing on stop band transitions and extinction ratios.

Main Results:

• Observed sharp stop band transitions in the pseudo-elliptic filter response.
• Demonstrated deep extinction ratios attributed to negative coupling.
• Confirmed the influence of coupling phase dispersion on spectral characteristics.

Conclusions:

• Negative coupling significantly impacts the spectral response, enabling sharp transitions and deep extinction.
• The findings validate the feasibility of advanced silicon microring devices.
• The 2D coupling topology supports general complex coupling coefficients for versatile device design.