Fig. 1. Terahertz spectra of water vapor^［25］

Fig. 2. Terahertz spectroscopic detection of gaseous substances

Fig. 3. Terahertz spectral detection of drugs

Fig. 4. Terahertz wave detection of corneal water content ^［47］

Fig. 5. A detection method for improving the quality of terahertz spectral signals of liquid phase substances

Fig. 6. TKE response of solution