Terahertz time-domain spectroscopy of D-glucose in the solution states

THz transmission spectrums of different glucose solution with concentration from 1% to 70% were measured on the condition of room temperature and fewer than 4% humidity in the nitrogen environment. According to the physical model of the THz optical parameters, their refractive indexes and absorption coefficients were gotten. The results showed that with the increase of glucose concentration, the THz absorption coefficients of solution decrease linearly. The fitting relations among the refractive index, the extinction coefficient, absorption coefficient and its concentration at the frequency of 0.33, 0.6 and 0.8 THz were acquired individually. Their correlation coefficients were larger than 0.95. Analysis and discussion about them were given. The THz time domain spectroscopy technologies could realize an accuracy measurement for the concentration of glucose solution. This work was meaningful to the exploration of THz spectral response of biological samples.