Terahertz Based Spectrum Scanning For Pharmaceutical Materials

Since people’s lives are better off nowadays, all kinds of drugs are being used byfamilies, it is rather important to ensure drug safety. Drug testing is crucial to the assuranceof drug safety, there lacks of efficient method for drug testing nowadays. With the frequencybetween0.1THz-10THz, terahertz has many unique properties compared to other lightsources: transient, high SNR, coherent, low energy, penetrating, strong absorbance to water,finger-print spectrum. It is now attracting more and more attention, and began to be used inmany different fields for its unique properties. And for its unique property of finger-printspectrum, terahertz can be used to measure drugs, to acquire their unique finger-printspectrums, namely absorbance spectrums. By setup a database of drug finger-prints of acertain scale, drug composition analysis and quality supervision can be conductedefficiently.We have Mini-Z and ABCD two THz-TDS systems in our lab, the first one generatesand detects THz by photoconductive antenna, and the other one uses strong laser to ionize airto generates and detects THz. With the manual tableting machine and molds, we compresssome common pharmaceutical materials into tablets. Then, we use the two systems,transmission type scanned the samples, acquired their unique finger-prints between thefrequency part of low frequency0.1THz-2THz and high frequency4THz-10THz. With theresults we achieved, we built a small absorption spectra database of those pharmaceuticalmaterials. After that, we scanned the absorbance spectrums of some simple compoundsamples, and identified them by comparing them to stored spectrums in database. At last,with the acquired results and phenomena, we verified the feasibility of THz being used indrug testing, and discussed the limitations of this technique for real-world application.