Abstract: The invention relates to a method, and a corresponding system, capable to check whether genuine SERS or SERRS taggants having a unique characteristic surface enhancement scattering feature are present or not on a machine-readable marking applied on a value document by using a Raman spectrometer adapted to perform a Raman Spectroscopy analysis of the marking. The method according to the invention allows a reliable and fast detection of a presence of the SERS/SERRS taggants, and is particularly suitable for checking authenticity of value documents, e.g. such as banknotes, moving with respect to the Raman spectrometer with a given speed, and possibly with a high speed, or briefly exposed to the Raman spectrometer.

Abstract: A reader operable to read a mark on a substrate, the reader comprising a power source, operable to deliver a variable drive current or voltage, a light source operable to illuminate said mark with a sequence of illumination light pulses of different wavelength spectra, an intensity of said illumination light pulses varying according to the delivered drive current or voltage, a light sensor operable to measure an intensity of light received from said mark and to deliver a corresponding light intensity signal, and a control unit operable to control said power source and light sensor to control timings of said illumination light pulses according to a switching pattern and timings to acquire said light intensity signal for synchronizing acquisition of said light intensity signal with said sequence of illumination light pulses, said control unit being further operable to adjust a duty cycle of said switching pattern so as to maintain heat generation associated to each illumination light pulse below a given thresho

Abstract: A reader operable to read a mark on a substrate, the reader comprising a power source, operable to deliver a variable drive current or voltage, a light source operable to illuminate said mark with a sequence of illumination light pulses of different wavelength spectra, an intensity of said illumination light pulses varying according to the delivered drive current or voltage, a light sensor operable to measure an intensity of light received from said mark and to deliver a corresponding light intensity signal, and a control unit operable to control said power source and light sensor to control timings of said illumination light pulses according to a switching pattern and timings to acquire said light intensity signal for synchronizing acquisition of said light intensity signal with said sequence of illumination light pulses, said control unit being further operable to adjust a duty cycle of said switching pattern so as to maintain heat generation associated to each illumination light pulse below a given thresho