Tunable Continuous-wave Terahertz Generator Based on Difference Frequency Generation with DAST Crystal

A tunable continuous-wave (CW) terahertz (THz) source with DAST crystal via difference frequency generation has been demonstrated in this work. The THz tuning range was from 1.1 THz to 3 THz and the maximum output power of the terahertz wave was 2.58nW at 2.52THz. The output spectrum of the CW-THz source is in good agreement with the air absorption lines in Hitran database. The linewidth of the output THz wave was estimated to be 56.5 MHz based on gas absorption spectrum. Therefore, the continuous-wave terahertz source will have good potential in THz high-precision spectroscopic detection and multispectral imaging.