Nanogap Enabled Trajectory Splitting and 3D Optical Coupling in Self-Assembled Microtubular Cavities

Area of Science:

• Photonics and optical engineering
• Nanotechnology and materials science

Background:

• Microcavities are crucial for light confinement and manipulation.
• Achieving strong optical coupling in 3D confined modes is challenging but essential for advanced photonic devices.

Purpose of the Study:

• To demonstrate the generation and strong coupling of multiple sets of 3D confined resonant modes within a single microtube cavity.
• To investigate the underlying mechanisms of resonant trajectory splitting and energy transfer in such systems.

Main Methods:

• Utilizing nanogap-induced resonant trajectory splits to engineer optical field overlap.
• Experimental mapping of spatial optical field distribution under strong coupling.
• Numerical calculations using a quasi-potential model and mode detuning analysis.

Main Results:

• Successful generation of multiple sets of 3D confined resonant modes in a single microtube.
• Demonstration of strong optical coupling evidenced by anticrossing features and mode changes.
• Direct observation of energy transfer between hybrid states through spatial field mapping.

Conclusions:

• The nanogap-induced resonant trajectory splitting effectively enables strong optical coupling of 3D modes.
• This approach offers a high degree of freedom for directional coupling and on-chip integration.
• Potential applications include multiplexing, 3D lasing, and advanced signal processing.