Fig. 1. Schematic diagram of (a) the proposed photosensitive structure, and (b) laser pump testing configuration

Fig. 2. Transmission spectrum of metamaterial structure for various silicon conductivities when electric field of terahertz wave was (a) perpendicular, and (b) parallel to the top two split gaps

Fig. 3. [in Chinese]

Fig. 4. (a) Real parts (ε’), and (b) imaginary parts (ε’’) of the complex permittivity of CaCl₂ solutions with different concentrations

Fig. 5. Peak responses of the sensor for different permittivities and the inset figure is the schematic diagram of the proposed structure coated with analyte

Fig. 6. Frequency shifts for different CaCl₂ molar concentrations