Study of a continuous-wave terahertz radiation source based on a vacuum photocathode diode

Area of Science:

• Physics
• Electrical Engineering
• Materials Science

Background:

• Terahertz (THz) technology holds significant potential for imaging, sensing, and communication.
• A primary limitation hindering THz technology advancement is the scarcity of efficient THz radiation sources.
• Existing THz source designs often lack integration and scalability.

Purpose of the Study:

• To design and develop a novel continuous-wave THz radiation source.
• To address limitations in physical mechanisms and simulation methods for THz devices.
• To explore micro-electro-mechanical systems (MEMS) fabrication for THz components.

Main Methods:

• Theoretical analysis of the vacuum photocathode diode mechanism.
• Development of a simulation methodology using COMSOL Multiphysics.
• Fabrication of critical components (miniaturized THz antenna, vacuum photocathode diode) using MEMS technology.

Main Results:

• Simulated radiated power exceeding 0.12 mW across 0.1-1.3 THz, with a peak of 1.27 mW at 0.2 THz.
• Achieved a current density of 142.6 mA/cm² in the vacuum diode under 450 mW laser excitation.
• Successful integration of semiconductor, vacuum, and optical electronics principles.

Conclusions:

• The designed vacuum photocathode diode represents a novel and effective continuous-wave THz radiation source.
• The developed systematic design methodology and MEMS fabrication approach provide a foundation for future THz source development.
• This research overcomes key bottlenecks, paving the way for broader applications of THz technology.