Photothermal Radiometry

We introduce a new analytical technique, by which contact-free spectroscopic studies of condensed matter can be performed. Photothermal radiometry (PTR) is based on pulse-wise illumination of a specimen by monochromatic radiation, and subsequent detection of attendant changes in the emission of thermal radiation from the sample. Infrared PTR absorption spectra recorded from powdered K2SO4 at temperatures 295-942 K are presented, to emphasize that PTR allows opaque and/or strongly scattering specimens to be studied directly.