Fig. 1. Schematic of the polarization detection system based on the longitudinal field component of a converging terahertz (THz) field

Fig. 2. Simulated results for extracting the polarizations of THz beams after passing through a polarizer and wave plate. (a) Simulated results for extracting the polarization of X-linearly polarized THz beams after passing through a polarizer with a 45° orientation; (b) simulated results for extracting the polarization of X-linearly polarized THz beams after passing through a 1/4 wave plate

Fig. 3. Simulated results for Jones matrix of a THz wave plate. (a) Schematic of the simulation process; (b) amplitude and phase distributions of Ez at 0.55, 0.75, 0.95 THz for incident and two transmitted THz fields; (c) curves of four Jones matrix elements as functions of the frequency

Fig. 4. Experimental system and measurement for the THz polarizers. (a) Schematic of a THz focal-plane imaging system for measuring the Ez component of a THz field; (b) amplitude and phase distributions of the Ez component at 0.55, 0.75, 0.95 THz; (c) Eb/Ea extracted from Ez components of the incident THz field and the transmitted THz fields through 45° and 135° polarizers; (d) corresponding Φa-Φb

Fig. 5. Experimental results of Jones matrix elements for THz polarizers. (a) Amplitude and phase curves of the Jones matrix elements of a THz polarizer with 45° orientation as function of the frequency; (b) amplitude and phase curves of the Jones matrix elements of a THz polarizer with 30° orientation as function of the frequency

Fig. 6. Sensitivity testing of the Jones matrix measurement method. (a)‒(d) Amplitude of J11, J12,J21, and J22 at 0.75 THz

Fig. 7. Measurement for the Jones matrix of THz wave plates. (a) Amplitude and phase curves of the Jones matrix elements of the wave plate with 30° orientation as function of the frequency; (b) amplitude and phase curves of the Jones matrix elements of the wave plate with 60° orientation as function of the frequency