Nonvolatile switchable electromagnetically induced transparency in terahertz range

Area of Science:

• Metamaterials and Nanophotonics
• Terahertz (THz) Technology
• Phase-Change Materials

Background:

• Terahertz (THz) frequency range offers potential for high-speed communication, sensing, and imaging.
• Dynamic control of THz waves is a significant challenge hindering practical applications.
• Metasurfaces offer a promising platform for manipulating electromagnetic waves.

Purpose of the Study:

• To design and demonstrate a switchable metasurface for dynamic terahertz wave modulation.
• To achieve switchable electromagnetically induced transparency (EIT) in the THz range using a phase-change material.
• To explore the potential of Ge-Sb-Te (GST) material for nonvolatile THz switching.

Main Methods:

• Fabrication of a metasurface with gold stripes on a Ge-Sb-Te (GST) sublayer.
• Theoretical analysis of quasi-bound-in-continuum (quasi-BIC) related EIT modes.
• Experimental validation of the metasurface's switching behavior and tunable EIT bandwidth.
• Utilizing the phase transition of GST to alter metasurface electrical properties.

Main Results:

• Demonstrated switchable electromagnetically induced transparency (EIT) in the terahertz frequency range.
• Achieved precise tuning of EIT bandwidth through geometric parameter adjustments and controlled asymmetry.
• Showcased robust, nonvolatile switching between transparent and opaque states via GST phase transition.
• Validated the design through theoretical analysis and experimental measurements.

Conclusions:

• The developed GST-based metasurface enables effective dynamic modulation of terahertz waves.
• This technology holds significant potential for advanced terahertz photonic devices and applications.
• The switchable EIT provides a novel mechanism for controlling THz wave propagation.