PHOTOACOUSTIC DETERMINATION OF OPTICAL-PARAMETERS OF TISSUE-LIKE MEDIA WITH REFERENCE TO OPTOACOUSTIC DIFFRACTION

Tissue optical properties are determined by an interpretation of press ure transients generated by irradiation with pulsed laser light. These pressure signals are detected using piezo-electric transducers. These signals are influenced by numerous processes during generation, propa gation and detection. Specific experiments were performed to study eac h process in particular using different substances with various absorp tion and scattering properties. Opto-acoustical diffraction effects ca use a strong distortion of the shape of the transients. This phenomeno n was investigated experimentally and verified theoretically.