Tunable Q-factor silicon microring resonators for ultra-low power parametric processes

Area of Science:

• Photonics
• Integrated Optics
• Nonlinear Optics

Background:

• Ring resonators are key components in integrated photonics for enhancing light-matter interactions.
• Precise control over resonator parameters like coupling coefficient and Q-factor is crucial for optimizing nonlinear optical processes.
• Fabrication variations can significantly impact resonator performance, necessitating post-fabrication tuning methods.

Purpose of the Study:

• To demonstrate a compact silicon ring resonator with simple electrical tuning capabilities.
• To enable post-fabrication trimming of the coupling coefficient and Q-factor.
• To enhance on-chip nonlinear optical processes, specifically four-wave mixing, through tunable resonant enhancement.

Main Methods:

• Fabrication of a compact silicon ring resonator.
• Implementation of an electrical tuning mechanism for the ring coupling coefficient.
• Post-fabrication trimming to overcome fabrication-induced variations.
• Characterization of the microring resonator's Q-factor and tuning across critical coupling.

Main Results:

• Demonstrated electrical tuning of the ring coupling coefficient and Q-factor.
• Achieved a tunable Q-factor range from 9,000 to 96,000.
• Showcased tunable efficiency for resonantly enhanced four-wave mixing (FWM) from -40 dB to -16.3 dB.
• Utilized ultra-low on-chip pump power of 0.7 mW for FWM.

Conclusions:

• The developed silicon ring resonator offers precise electrical control over critical parameters.
• This tuning capability effectively compensates for fabrication variations and optimizes resonator performance.
• The device enables efficient, tunable nonlinear optical processes like FWM at low power levels on-chip.