High speed terahertz modulation from metamaterials with embedded high electron mobility transistors

Area of Science:

• Terahertz (THz) science and technology
• Semiconductor device physics
• Metamaterials engineering

Background:

• Metamaterials offer unique electromagnetic properties but often lack electrical tunability.
• High Electron Mobility Transistors (HEMTs) are advanced semiconductor devices with high-frequency capabilities.
• Integrating active components like HEMTs into metamaterials is crucial for dynamic control.

Purpose of the Study:

• To develop and characterize a novel hybrid terahertz device by integrating metamaterials with pseudomorphic high electron mobility transistors (HEMTs).
• To demonstrate electrical tunability and modulation capabilities of the metamaterial at terahertz frequencies.
• To explore the feasibility of using mature gallium arsenide (GaAs) semiconductor processes for advanced THz device fabrication.

Main Methods:

• Computational modeling and experimental fabrication of metamaterial-HEMT hybrid devices.
• Utilizing a commercial gallium arsenide (GaAs) fabrication process.
• Characterization using terahertz time-domain spectroscopy (THz-TDS).

Main Results:

• Successful monolithic integration of HEMTs into metamaterial unit cells.
• Demonstrated modulation of terahertz signals at the metamaterial's resonant frequency (0.46 THz).
• Achieved switching values exceeding 30% and terahertz modulation up to 10 megahertz (MHz).

Conclusions:

• The hybrid metamaterial-HEMT device shows significant potential for electrically tunable terahertz applications.
• Mature semiconductor fabrication processes can be leveraged for advanced metamaterial device integration.
• This work establishes a new pathway for developing dynamic and reconfigurable terahertz systems.