Integrated array of coupled exciton-polariton condensates

Area of Science:

• Quantum optics
• Materials science
• Nanotechnology

Background:

• Controlled coupling of individual polariton condensates is crucial for polariton-based circuits.
• Current methods using etched or epitaxially grown microcavities are complex and limit coupling.
• A scalable and efficient coupling method is needed for integrated quantum photonic devices.

Purpose of the Study:

• To introduce a novel lithographically defined silicon platform for scalable polariton condensate coupling.
• To investigate the coupling mechanisms and energy shifts in arrays of polariton condensates.
• To demonstrate the potential for integrated polariton devices and quantum photonic networks.

Main Methods:

• Utilized a silicon-based platform with high-contrast grating (HCG) microcavities and a π-conjugated polymer.
• Investigated doublet and N-coupled condensate arrays to observe mode hybridization and energy shifts.
• Employed transition-matrix multi-scattering simulations and tight-binding modeling for quantitative support.
• Performed first-order coherence measurements using Michelson interferometry.

Main Results:

• Demonstrated mode hybridization into bonding and antibonding states in doublet cavities mediated by shared HCG mirrors.
• Observed systematic red-shifts in condensate energy and progressive threshold reduction in N-coupled arrays.
• Confirmed spatially extended condensates with exponentially decaying temporal coherence via interferometry.
• Experimental findings were quantitatively validated by theoretical simulations.

Conclusions:

• Established a scalable route for controlled coupling of polariton condensates using a silicon-based HCG platform.
• The developed platform facilitates the creation of integrated polariton devices.
• This work paves the way for advanced quantum photonic networks.