Compact tunable electromagnetically induced transparency and Fano resonance on silicon platform

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Electromagnetically induced transparency (EIT) and Fano resonances are crucial quantum interference phenomena.
• On-chip implementation of these effects is vital for integrated photonic devices.

Purpose of the Study:

• To propose and demonstrate an on-chip coupling resonant system for generating EIT-like effects and Fano resonances.
• To investigate the influence of microring resonator coupling conditions on resonance phenomena.
• To achieve tunable Fano resonances on a silicon platform.

Main Methods:

• Fabrication of an on-chip system comprising a microring resonator (MRR) and cascaded Sagnac-loop mirrors (SLMs) assisted Fabry-Perot (FP) cavity.
• Theoretical analysis of MRR coupling conditions (over-coupling for EIT-like, under-coupling for Fano resonance).
• Experimental demonstration using an add-drop MRR under coupled conditions, with thermal-optic tuning via a micro-heater.

Main Results:

• Observed Fano resonances with a sharp asymmetric line shape under the under-coupling condition.
• Achieved maximum extinction ratio (ER) of 23.22 dB and maximum slope rate (SR) of 252 dB/nm for Fano resonances.
• Demonstrated wide wavelength tunability of Fano resonances with a tuning efficiency of 0.2335 nm/mW.

Conclusions:

• The proposed on-chip system successfully generates EIT-like effects and Fano resonances on a silicon platform.
• The system allows for dynamic tuning of Fano resonance wavelengths, enabling practical applications.
• The achieved high ER and SR highlight the potential of this silicon photonics approach.