Terahertz Time-domain Spectroscopy Signature of Animal Tissues

摘要

The terahertz time-domain spectroscopy becomes a promising technology in studies of biological tissues, genetic analysis, and cancer diagnosis. Due to the fact that biological tissues possess high level of hydration, it results in strong absorption at terahertz frequencies. Here, we present terahertz time-domain spectroscopy characterization of animal tissues, including skin, fat, and muscles from porcine and rat samples. The experimental data reveal different frequency-dependent responses to terahertz radiation for difference types of tissues from these two animals. As being consistent with the estimation from the time-domain transmitted pulses and the corresponding spectra, the absorption coefficient of skin tissue is obviously lower than that of muscle by an average of 10%. Compared to skin and muscle, the fat tissue shows extremely low absorption at terahertz frequencies due to very low water content. At 0.5 THz, the power absorption coefficients of skin and lean pork are all above 100 cm-1, while it is only 15 cm-1 for porcine fat.