Electrically controlled terahertz modulator with deep modulation and slow wave effect via a HEMT integrated...

Area of Science:

• Terahertz (THz) technology
• Metamaterials and Plasmonics
• Semiconductor device engineering

Background:

• Terahertz (THz) modulators are crucial for high-speed communication and sensing.
• Achieving deep and fast modulation in THz modulators remains a challenge.
• Existing methods for electrical control of slow wave effects are often complex or inefficient.

Purpose of the Study:

• To propose and demonstrate a novel electrically controlled THz modulator.
• To leverage slow wave effects and localized fields for enhanced modulation performance.
• To introduce a new mechanism for high-performance THz modulation using HEMT-integrated metasurfaces.

Main Methods:

• Integration of a high electron mobility transistor (HEMT) with a metasurface structure.
• Electrical control of resonant modes through HEMT switches.
• Utilizing the confined electric field within the HEMT-embedded region.
• Analysis of slow wave effects and their impact on modulation.

Main Results:

• Achieved a high modulation depth of 96%.
• Demonstrated a significant group delay of 10.4 ps, indicative of the slow wave effect.
• Successfully controlled resonant modes electrically via HEMT switches, a novel approach.

Conclusions:

• The proposed HEMT-integrated metasurface offers a new and effective mechanism for THz modulation.
• The combination of slow wave effect and localized field leads to high-performance modulation.
• This work paves the way for advanced, electrically controlled THz modulators.