A method and system for luminescence molecular imaging or tomography of a region of interest in a scattering medium is disclosed. The system comprises a non-linear luminescent marker material arranged in the scattering medium, one or more light sources positioned by at least one light source position for exciting said luminescent marker by excitation light emitted by said one or more light sources into an excitation volume, a detector at a luminescent light detection position detecting luminescence from said luminescent marker due to said excitation light, wherein said excitation light comprises pulsed excitation light.