Device, system and method for quantifying fluorescence and optical properties

Methods, devices and systems for quantifying fluorescence and optical properties in a turbid medium such as tissue are disclosed. One of the methods comprises: providing fluorescence emission and reflectance wavelengths detected from a target surface where each of the detected wavelengths is associated with a respective known distance between a respective excitation source giving rise to the respective detected wavelength and a detector detecting the respective detected wavelength; and calculating the optical properties based on the detected wavelengths and the respective known distances. The known distances may be predetermined to enable calculation of a desired range of values for the optical properties. The calculation of the optical properties may be based on a model of light interaction with the turbid medium where the model limits a range of calculated values for the optical properties.