Strong Coupling in All-Dielectric Intersubband Polaritonic Metasurfaces.

Area of Science:

• Photonics and light-matter interactions
• Dielectric metasurfaces
• Semiconductor heterostructures

Background:

• Mie-resonant dielectric metasurfaces are key for light-matter studies and applications like holography and sensing.
• Current applications often rely on weak light-matter interactions, limiting performance.
• Strong coupling is crucial for advanced optical functionalities.

Purpose of the Study:

• To demonstrate strong polaritonic coupling between Mie photonic modes and intersubband (ISB) transitions.
• To explore tailoring of coupling strength by engineering metasurface and semiconductor properties.
• To develop a novel, loss-free approach for generating intersubband polaritons.

Main Methods:

• Fabrication of all-dielectric metasurfaces.
• Integration with semiconductor heterostructures exhibiting intersubband transitions.
• Spectroscopic analysis to confirm strong coupling and measure Rabi splitting.

Main Results:

• First demonstration of strong polaritonic coupling between Mie modes and ISB transitions.
• Achieved significant Rabi splitting up to 10%.
• Showcased tunability of coupling strength via material and resonator engineering.
• All-dielectric approach avoids ohmic losses and optical damage issues inherent in plasmonics.

Conclusions:

• This work establishes a new paradigm for engineering intersubband polaritons using dielectric metasurfaces.
• The demonstrated strong coupling and tunability pave the way for novel mid-infrared devices.
• The loss-free, high-damage-threshold nature of this approach is ideal for compact nonlinear optical sources.