The invention relates to a method and a device, suitable for the measurement of quantitative photon absorption coefficient in tissue, wherein the device comprises a first light source, suitable for generating photons, a light measurement element suitable for measuring at least one of: the intensity, the frequency, the frequency deviations and phase shift of the light to be measured, an ultrasound source, suitable for the generation of a defined sound wave pattern in a defined volume element within the tissue, wherein the ultrasound source is suitable for labelling the light, originating from the first light source or a second light source that enters the defined volume element within the tissue, and an ultrasound measurement element, suitable for measuring ultrasound, originating from the defined volume element within the tissue and generated by the light of the first light source that enters the defined volume element within the tissue.