Laser Absorption Spectroscopy with an ATR Prism

The use of lasers as light sources in IR spectroscopy allows an improvement in measuring sensitivity by a factor of about 100 compared with the conventional technique. In addition, the monochromaticity of lasers appreciably improves the resolution. Combining lasers with an ATR plate acting as test prism gets rid of transmission cells without impairing the measuring sensitivity. It also considerably reduces the thennal load on the test sample; in vivo measurements on biological tissue can thus be made in a simple manner.