Pulse-width dependence of terahertz parametric generation in the sub-picosecond regime

Area of Science:

• Nonlinear optics
• Terahertz (THz) science and technology
• Solid-state physics

Background:

• Terahertz (THz) parametric generation is a key technique for producing THz radiation.
• Ultrashort pulsed lasers enable advanced nonlinear optical phenomena.
• Lithium niobate (LiNbO3) is a widely used nonlinear optical crystal.

Purpose of the Study:

• To investigate the generation characteristics of THz parametric generation in the ultrashort pulse regime.
• To determine the phase stability of the generated THz waves.
• To explore the potential of this method for developing novel THz sources.

Main Methods:

• Experimental setup for ultrashort pulse generation.
• Utilizing lithium niobate (LiNbO3) as the nonlinear medium.
• Measuring THz parametric generation threshold and phase stability.

Main Results:

• Parametric gain observed in LiNbO3 for ultrashort pulses.
• Generation threshold identified at approximately 700 fs pulse width.
• High inter-pulse phase stability of the generated THz waves demonstrated.

Conclusions:

• Ultrashort pulse THz parametric generation in LiNbO3 is feasible.
• The observed threshold correlates with the crystal's Raman linewidth.
• This technique provides a foundation for broadband pulsed THz sources for spectroscopy.