Investigation on terahertz generation at polariton resonance of MgO:LiNbO3 by difference frequency generation

• Terahertz wave generation at polariton resonance of MgO:LiNbO3 is investigated.
• Frequency tuning characteristics of terahertz wave are numerically analyzed.
• Gain coefficient of terahertz wave at polariton resonance is analyzed.

Terahertz (THz) wave generation at polariton resonance of MgO:LiNbO3 with a surface-emitted configuration is investigated. It is shown that by using crystal birefringence of bulk MgO:LiNbO3 crystal THz wave can be efficiently generated by difference frequency generation (DFG) in the vicinity of polariton resonances with Cherenkov phase matching scheme. The frequency tuning characteristics of THz wave via varying wavelength of difference frequency waves, phase matching angle and working temperature are numerically analyzed. Parametric gain coefficient in the low-loss limit and absorption coefficient of THz wave during DFG process in the vicinity of polariton resonances are analyzed.