High-sensitive terahertz detection by parametric up-conversion using nanosecond pulsed laser

Abstract

A high-sensitive terahertz detector operating at room temperature was demonstrated based on parametric up-conversion. A nanosecond 1064-nm Nd:YAG laser was used to pump the parametric up-conversion detector and the up-conversion from terahertz wave to NIR laser was realized in a lithium niobate crystal. The minimum detectable terahertz energy of 9 pJ was realized with the detection dynamic range of 54 dB, which was three orders of magnitude higher than that of commercial Golay cell. The detectable terahertz frequency range of the detection system was 0.90 Thz–1.83 THz. Besides, the effects of pump energy and effective gain length on the detection sensitivity were studied in experiment. The results showed that higher pump energy and longer effective gain length are helpful for improving the detection sensitivity of parametric up-conversion detector.