Towards higher frequencies in a compact prebunched waveguide THz-FEL

Area of Science:

• Physics
• Engineering

Background:

• Free-electron-lasers (FELs) are crucial for generating tunable, high-power terahertz (THz) radiation.
• Waveguides enhance electron-photon coupling in THz FELs, enabling efficient radiation generation.

Purpose of the Study:

• To characterize the spectral properties of a compact waveguide THz FEL.
• To investigate simultaneous lasing at multiple frequencies and wavelength tunability.

Main Methods:

• Utilizing a waveguide within a THz FEL setup.
• Varying electron beam energy to tune radiation wavelength.
• Ensuring prebunched electron injection at the resonant wavelength scale.

Main Results:

• Demonstrated simultaneous lasing at two distinct frequencies.
• Successfully tuned the radiation wavelength in the high-frequency branch by adjusting beam energy.
• Confirmed the influence of waveguide dispersion on radiation characteristics.

Conclusions:

• Waveguide THz FELs provide a versatile platform for generating tunable, high-power THz radiation.
• The spectral properties, including frequency and bandwidth, are significantly influenced by waveguide dispersion and electron beam parameters.