Enhancing the efficiency of waveguide terahertz free-electron lasers using a bow-tie cavity

Area of Science:

• Physics
• Laser Technology
• Optics

Background:

• Free-electron lasers (FELs) are crucial for terahertz (THz) radiation generation, offering high power and tunability.
• Optical waveguides enhance THz FEL efficiency but can cause spectral gap issues.
• Existing THz FEL designs face limitations in spectral coverage and performance.

Purpose of the Study:

• To develop a novel, compact waveguide THz FEL design.
• To address and mitigate the spectral gap phenomenon in THz FELs.
• To improve long-wavelength performance and laser output.

Main Methods:

• Integration of an optical waveguide within a THz FEL.
• Implementation of a novel bow-tie cavity configuration.
• Design and simulation of a 50-600 μm FEL.

Main Results:

• The bow-tie cavity effectively prevents the spectral gap phenomenon.
• Significant improvement in long-wavelength laser performance was achieved.
• Tens of microjoules of micro-pulse energy and megawatt peak powers were obtained across 50-600 μm.

Conclusions:

• The compact waveguide THz FEL with a bow-tie cavity offers a promising solution for advanced THz sources.
• This design enhances efficiency and spectral performance, overcoming previous limitations.
• The demonstrated capabilities pave the way for new applications in THz science and technology.