Effects of photo-induced insulator–metal transition on terahertz radiation characteristics of Pr0.7Ca0.3MnO3

Abstract Terahertz (THz) radiation characteristics have been investigated for a dipole-type photoconducting switch fabricated on a charge-ordered manganite Pr 0.7 Ca 0.3 MnO 3 thin film. As the bias voltage is swept at a constant temperature of 125 K and a fixed laser power of 50 mW, we found a complete suppression of THz radiation, while the photocurrent returns to the original value with a hysteresis. We briefly discuss its interesting THz radiation characteristics related to the occurrence of photo-induced insulator–metal transition.