Scalable terahertz generation by large-area optical rectification at 80 TW laser power

Area of Science:

• • Physics
• • Optics
• • Materials Science

Background:

• • Terahertz (THz) generation is crucial for various scientific and technological applications.
• • Optical rectification in nonlinear crystals is a common THz generation method.
• • Existing methods often face limitations in energy conversion efficiency and scalability.

Purpose of the Study:

• • To demonstrate high-energy THz generation using a large-aperture lithium niobate (LiNbO3) wafer.
• • To investigate the efficiency and scalability of this THz generation scheme.
• • To compare the performance with existing THz generation materials like Zinc Telluride (ZnTe).

Main Methods:

• • Employed a femtosecond laser with energy up to 2 Joules (J).
• • Utilized optical rectification within a bulk LiNbO3 crystal.
• • Focused on THz emission from the rear surface of the LiNbO3 wafer.

Main Results:

• • Achieved 0.19 millijoules (mJ) of THz energy.
• • Demonstrated laser-to-terahertz conversion efficiencies of approximately 10^-4.
• • Showed a ~3 times improvement in efficiency compared to ZnTe at 800 nm pumping.

Conclusions:

• • The demonstrated scheme offers a simple yet effective method for high-energy THz generation.
• • The LiNbO3-based approach is scalable for multimillijoule THz output with petawatt laser systems.
• • This advancement holds promise for future THz spectroscopy and imaging applications.