Demonstration of a tilted-pulse-front pumped plane-parallel slab terahertz source

Area of Science:

• Nonlinear optics
• Terahertz (THz) science and technology
• Laser-driven THz generation

Background:

• Terahertz (THz) radiation is crucial for various scientific and technological applications.
• Efficient and scalable generation of high-energy THz pulses remains a challenge.
• Existing THz sources often lack beam quality or scalability.

Purpose of the Study:

• To demonstrate a new type of tilted-pulse-front pumped THz source.
• To investigate the generation of single-cycle THz pulses with high energy.
• To explore the potential for scaling THz generation efficiency and output energy.

Main Methods:

• Utilizing a lithium niobate (LiNbO3) plane-parallel slab with an echelon structure.
• Employing a tilted-pulse-front pumping technique with a Ti:sapphire laser.
• Characterizing the generated THz pulses for energy, frequency, and beam properties.

Main Results:

• Successfully generated single-cycle THz pulses with 1 μJ energy and 0.30 THz central frequency.
• Achieved a conversion efficiency of 5×10⁻⁴.
• Demonstrated a scalable THz source with potential for symmetric beams and good focusability.

Conclusions:

• The demonstrated LiNbO3 echelon-based THz source is a promising platform for high-energy THz generation.
• Future improvements, including cryogenic cooling and optimized echelon design, are expected to increase efficiency by an order of magnitude.
• The plane-parallel geometry facilitates scaling to high THz pulse energies and producing high-quality beams.