Fig. 1. Waveforms of THz pulse before and after passing through sample

Fig. 2. Comparison of abnormal data of transmission coefficient before and after filtering

Fig. 3. Amplitude of transmission coefficient of sucrose before and after filtering

Fig. 4. Amplitudes of absorption coefficient and transmission coefficient of sucrose

Fig. 5. Refractive index of sucrose

Fig. 6. Amplitudes of absorption coefficient and transmission coefficient of benzophenone