Department of Physics, Faculty of Science, Tokyo University of Science, 1–3 Kagurazaka, Tokyo 162–8601, Japan.
Opt Lett. 2012 Jul 1;37(13):2655-7. doi: 10.1364/OL.37.002655.
Photothermal deflection spectroscopy is combined with a Sagnac interferometer to enhance the sensitivity of the absorption measurement by converting the photothermal beam deflection effect into the light intensity change by the interference effect. Because of stable light interference due to the common path, the signal intensity can be amplified without increasing the noise by extending the optical path length between a sample and a photodetector. The sensitivity is further improved by the use of focusing optics and double-pass geometry. This makes photothermal deflection spectroscopy applicable to any kind of material in the whole visible region with a xenon lamp for excitation and water or air as a deflection medium.
光热偏转光谱学与萨格纳克干涉仪相结合，通过将光热光束偏转效应转换为干涉效应引起的光强变化，从而提高吸收测量的灵敏度。由于公共光路的稳定干涉，通过延长样品和光电探测器之间的光路长度，可以在不增加噪声的情况下放大信号强度。通过使用聚焦光学器件和双通几何结构，灵敏度得到进一步提高。这使得光热偏转光谱学适用于任何种类的材料，在整个可见光区域内，使用氙灯作为激发光源，水或空气作为偏折介质。
