Ultrabright continuously tunable terahertz-wave generation at room temperature.

Area of Science:

• Physics
• Optics
• Materials Science

Background:

• Terahertz (THz) waves occupy a critical frequency gap between microwaves and infrared.
• Existing THz sources struggle to produce high-brightness beams, limiting research and applications.
• The demand for advanced THz sources is increasing across various scientific disciplines.

Purpose of the Study:

• To demonstrate a novel method for generating ultrabright terahertz waves.
• To overcome the limitations of current terahertz radiation sources.
• To enable new research avenues in the terahertz frequency range.

Main Methods:

• Utilized parametric wavelength conversion in a nonlinear crystal (LiNbO3).
• Employed stimulated Raman scattering, specifically avoiding stimulated Brillouin scattering.
• Leveraged recently developed microchip laser technology.
• Applied nonlinear up-conversion techniques for visualization and frequency determination.

Main Results:

• Achieved ultrabright terahertz waves with brightness ~0.2 GW/sr·cm(2) and peak power >50 kW.
• Demonstrated a brightness temperature of ~10(18) K, significantly exceeding specialized sources like free-electron lasers.
• Successfully visualized intense terahertz waves and determined their frequency.

Conclusions:

• The developed method provides a significantly brighter terahertz source than previously available.
• This advancement is expected to accelerate applied research in the terahertz region.
• The new source is poised to open up novel research fields, including nonlinear terahertz optics.