High-efficiency terahertz-wave generation based on extended interaction oscillator with strongly-coupled 2π mode...

Area of Science:

• Physics
• Electrical Engineering
• Electromagnetics

Background:

• Extended Interaction Oscillators (EIOs) are crucial for generating high-frequency terahertz (THz) radiation.
• Optimizing slow-wave structures (SWS) is essential for enhancing the electronic efficiency and output power of EIOs.
• Achieving efficient operation in the 2π-mode is a key challenge in EIO design.

Purpose of the Study:

• To investigate a novel bi-periodic slow-wave structure (BPSWS) for improving the 2π-mode electronic efficiency of an EIO.
• To enhance the coupling performance and output characteristics of the EIO operating at 0.22 THz.
• To validate the proposed BPSWS design through particle-in-cell (PIC) calculations and cold-test experiments.

Main Methods:

• Design and simulation of a 2π-mode bi-periodic slow-wave structure (BPSWS) with staggered slots.
• Utilizing particle-in-cell (PIC) calculations to evaluate electronic efficiency and performance metrics.
• Conducting cold-test experiments to verify fabrication precision, consistency, and frequency response.

Main Results:

• The BPSWS achieved an electronic efficiency of 6.52% at 0.22 THz.
• Key parameters such as characteristic impedance (M²R/Q), coupling coefficient, and normalized wave-amplitude were significantly improved compared to mono-periodic SWS.
• The BPSWS-EIO demonstrated a potential for 503 W average output power with a sheet beam.
• Cold-test experiments confirmed the structure's fabrication precision and expected frequency response.

Conclusions:

• The proposed BPSWS effectively enhances the 2π-mode operation of EIOs, leading to improved electronic efficiency and output power.
• The BPSWS offers a promising solution for high-performance terahertz sources.
• The validated design shows excellent potential for practical applications requiring efficient THz generation.