Curved Nanomembrane-Based Concentric Ring Cavities for Supermode Hybridization

Area of Science:

• Photonics and optical physics
• Nanotechnology and materials science

Background:

• Whispering gallery mode (WGM) resonances are crucial in optical cavities.
• Concentric dual ring cavities offer unique mode confinement and interaction possibilities.

Purpose of the Study:

• To investigate mode interactions and resonant hybridization in nanomembrane-formed concentric dual ring cavities.
• To demonstrate control over coupling strength and supermode behavior in these hybrid cavities.

Main Methods:

• Fabrication of dual concentric microring cavities using rolled-up nanomembranes with a subwavelength-thickness interlayer.
• Utilizing high-index nanomembranes on inner and outer surfaces of the dielectric nanomembrane.
• Spatially resolved measurements along the cavity axial direction to detune coupled supermodes.

Main Results:

• Observation of mode splitting into symmetric and antisymmetric modes in the dual ring system.
• Demonstration of spectral anticrossing, indicating strong coupling between modes.
• Observation of superwaves oscillating between concentric rings with opposite phase upon strong coupling.
• Tunable coupling strength by varying the spacer layer thickness, enabling switching between strong and weak coupling regimes.

Conclusions:

• The developed hybrid cavity system enables novel cavity mode interactions through resonant hybridization.
• The system offers high flexibility in controlling coupling strength, crucial for fundamental and applied studies.
• This compact and robust scheme using curved nanomembranes paves the way for advanced optical device applications.