| Terahertz radiation (0.1~10THz) is the gap between microwave and far-infrared region.Before the middle of 1980s,characteristic of THz radiation is rarely known because of lacking effective generation and detection methods. With the development of ultra-fast laser in recent years,stable and reliable methods are available for THz generation and detection. We apply THz techniques in Traditional Chinese Medicine for the first time and obtain some meaningful experimental results.THz time-domain spectroscopy (TTDS) is a powerful tool developed in 1990s for spectroscopy measurement.This technique can record the amplitude of the wave by electro-optical or photoconductive sampling.After fast Fourier transform,the amplitude and phase of the THz pulse wave is given,then the refractive index and absorption of the material in THz region is extracted.Biology is one of the new interests of TTDS in recent years(including study of protein and DNA's THz spectroscopy).While Fourier Transform Infrared_Raman Spectroscopy is used in Traditional Chinese Medicine's identification in Tsinghua University, multi-subject research must be developed for the difficult and pressing task.Applied in Traditional Chinese Medicine's identification,THz radiation has both advantages and difficulties. 1), Some vibrational and rotational modes of Traditional Chinese Medicines' biomoleculars are in THz region.2, Dispersion spectroscopy of Traditional Chinese Medicine is available in THz region, while not in infrared region.3), Phase information is available as THz radiation is coherent.4), With the pulse width of picosecond and femtosecond,THz radiation can be used to measure the time-domain spectroscopy and transient characteristicof Traditional Chinese Medicines.THz technology is a promising method for Traditional Chinese Medicine's Identification.In this paper,THz Time-Domain Spectroscopy is used to study Traditional Chinese Medicines.The following is a brief summary of the works conducted in this thesis and the experimental results achieved.1,Jsing the transmission TTDS,we measured and analyzed angelica sinensis (Oliv.) Diels, poria cocos (Schw) Wolf, citrus aurantium L. and isatis indigotica Fort. A model developed by T.D.Dorny and L.Duvillaret et al is used to discuss the principle and method for optical constants extracting.Through the comparison among the four samples' THz spectroscopy,we find that different medicines have different THz spectroscopy with different peak location,different absorption coefficient and different refractive index.The differences may come from the difference of component and content.2.Through the comparison among the THz spectroscopy of Ginkgo bilaba extract from five different manufacturers and the standard sample of the national pharmacopoeia,we find that medicines and the standard sample have different THz spectroscopy and medicines from different manufacturers have different THz spectroscopy.These differences may come from the difference of assistant materials and manufacturing process.3,Through the comparison among Arteannuin and its three ramifications (Dihydroartemisinin, Artemether and Artesunate)' THz spectroscopy, we find that the difference of molecular structures of Arteannuin, Dihydroartemisinin,Artemether and Artesunate can be showed in THz spectroscopy.THz spectroscopy is sensitive to the change of molecular structure and has potential in Traditional Chinese Medicine's Identification.4,The method of making Traditional Chinese Medicines samples in THzregion is discussed in detail.Methods of making samples in mid-infrared region and other samples in THz region are also reviewed.The following experiment results show that pure Traditional Chinese Medicines pellets are fit for THz spectroscopy measurement.5 ,Using IR Spectroscopy, we also measured Ginkgo bilaba extract, Arteannuin and its three ramifications. THz spectroscopy and Infrared spectroscopy of these Traditional Chinese Medicines are compared. The same peak 514cm-1 is detected in both THz spectroscopy and IR spectroscopy of Arte...
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