Allard Jean-François, Cornet Alain, Debacq Christophe, Meurens Marc, Houde Daniel, Morris Denis
Département de radiobiologie et médecine nucléaire, Université de Sherbrooke, Sherbrooke, Québec, Canada.
Opt Express. 2011 Feb 28;19(5):4644-52. doi: 10.1364/OE.19.004644.
We report quantitative measurement of the relative proportion of δ- and β-D-mannitol crystalline phases inserted into polyethylene powder pellets, obtained by time-domain terahertz spectroscopy. Nine absorption bands have been identified from 0.2 THz to 2.2 THz. The best quantification of the δ-phase proportion is made using the 1.01 THz absorption band. Coherent detection allows using the spectral phase shift of the transmitted THz waveform to improve the detection sensitivity of the relative δ-phase proportion. We argue that differential phase shift measurements are less sensitive to samples' defects. Using a linear phase shift compensation for pellets of slightly different thicknesses, we were able to distinguish a 0.5% variation in δ-phase proportion.
我们报告了通过时域太赫兹光谱法对插入聚乙烯粉末颗粒中的δ-和β-D-甘露醇结晶相的相对比例进行的定量测量。已在0.2太赫兹至2.2太赫兹范围内识别出九个吸收带。使用1.01太赫兹吸收带对δ相比例进行了最佳定量。相干检测允许利用透射太赫兹波形的光谱相移来提高相对δ相比例的检测灵敏度。我们认为差分相移测量对样品缺陷不太敏感。通过对厚度略有不同的颗粒进行线性相移补偿，我们能够区分出δ相比例0.5%的变化。
