Terahertz Generation by Optical Rectification of 780 nm Laser Pulses in Pure and Sc-Doped ZnGeP2 Crystals

Terahertz wave generation through the optical rectification of 780 nm femtosecond laser pulses in ZnGeP2 crystals has been studied. All possible interactions types I and II were analyzed by modeling experimentally. We demonstrate possibility broadband “low-frequency” terahertz an ee–e interaction (with two pumping waves a generated wave; all these had extraordinary polarization crystal) “high-frequency” oe–e interaction. The arising achieving narrowing bandwidth at using thicker is experimentally confirmed. It found that thermal annealing as-grown their doping with 0.01 mass % Sc reduces absorption “anomalous absorption” region (λ = 0.62–3 μm). oo–e (110) ZnGeP2:Sc equal thicknesses was compared. more efficient for rectification.