<title>Pulsed photothermal radiometric investigations of optical and thermal properties</title>

Abstract

The knowledge of laser tissue interaction, the light propagation in tissue and thus its optical properties are of fundamental importance for both laser treatment and diagnostics. We use the method of pulsed photothermal radiometry (PPTR) to evaluate optical or thermal properties of tissue-like phantoms. Because its a non-destructive and non-contact technique its a promising tool for tissue optics in vivo. As phantoms we used gelatine of known optical properties with ink added as absorber. Once the thermal features are known, one can determine the optical properties of the sample and vice versa. PPTR investigations of absorption coefficients were compared to other methods such as time resolved stress detection and optical transmission measurements. PPTR is a suitable tool to perform spectroscopy under conditions of high pressure and/or temperature and can therefore be used to investigate the ablation process.