High-efficiency terahertz pulse generation via optical rectification by suppressing stimulated Raman scattering...

Area of Science:

• Optics and Photonics
• Condensed Matter Physics
• Materials Science

Background:

• Terahertz (THz) pulse generation is crucial for various scientific and technological applications.
• Lithium niobate (LiNbO3) is a promising material for nonlinear optical processes, including THz generation.
• Stimulated Raman scattering (SRS) and group velocity dispersion (GVD) in LiNbO3 can affect excitation pulse quality and THz generation efficiency.

Purpose of the Study:

• To experimentally demonstrate high-efficiency THz pulse generation via optical rectification in LiNbO3.
• To investigate the interplay between spectral broadening, SRS, and GVD in LiNbO3 for THz generation.
• To optimize THz generation efficiency by controlling the excitation pulse bandwidth.

Main Methods:

• Experimental setup for THz pulse generation using optical rectification in LiNbO3.
• Utilizing spectral broadening of the excitation pulse via SRS.
• Implementing bandwidth control of the excitation pulse to mitigate GVD effects.
• Measuring energy conversion efficiency from optical to THz pulses.

Main Results:

• High-efficiency THz pulse generation was experimentally demonstrated in LiNbO3.
• Spectral broadening via SRS was observed to coincide with efficient THz generation.
• Undesired excitation pulse stretching due to high GVD in LiNbO3 was mitigated.
• The highest reported energy conversion efficiency of 0.21% for THz pulse generation was achieved.

Conclusions:

• Bandwidth control of the excitation pulse is critical for optimizing THz generation efficiency in LiNbO3.
• The study achieved a record conversion efficiency, highlighting the potential of LiNbO3 for THz applications.
• This work provides a pathway for efficient and controlled THz pulse generation using nonlinear optical methods.