Near-infrared modulation by means of GeTe/SOI-based metamaterial

Area of Science:

• Nanophotonics
• Metamaterials
• Optical Engineering

Background:

• Silicon-on-insulator (SOI) technology lacks easily implementable modulators.
• Chalcogenide phase change materials (PCMs) offer tunable optical properties in the near-infrared spectrum.
• All-dielectric metamaterials provide resonant behavior without ohmic losses in the telecom range.

Purpose of the Study:

• To investigate a novel hybridization of SOI-based metamaterials with the PCM GeTe.
• To demonstrate a tunable nanophotonic component for near-infrared applications.

Main Methods:

• Design and fabrication of a metamaterial comprising Si nanorods coated with a thin layer of GeTe.
• Experimental characterization of the optical response upon switching GeTe's phase.
• Confocal Raman imaging to identify crystallized zones within the metamaterial unit cell.

Main Results:

• The hybrid SOI-GeTe metamaterial exhibits significant resonance-governed reflection contrast at 1.55 μm when GeTe transitions from amorphous to crystalline state.
• Experimental findings align well with numerical simulations.
• Successful differentiation of crystallized zones using confocal Raman imaging.

Conclusions:

• The developed hybrid metamaterial shows promise for all-dielectric tunable near-infrared nanophotonics.
• This approach offers a pathway for integrating tunable functionalities into existing SOI platforms.
• The GeTe material provides a viable mechanism for optical modulation in nanophotonic devices.