Optically-based system for processing banknotes based on security feature emissions

A method and a system are disclosed for processing a banknote. The method includes providing a banknote having at least one photonically active security feature, the banknote being moved along a conveyance path; illuminating the at least one security feature with light from a stimulus source; identifying a location of the at least one security feature by detecting an emission from the security feature; directing an excitation source at the identified location; illuminating the at least security feature with light from the excitation source; and detecting a further emission from the photonically active security feature in response to the light from the excitation source. The step of identifying may include operating a linescan camera having scan axis that is parallel to a conveyance axis, or a scan axis that is perpendicular to the conveyance axis. The step of identifying may also include operating a single element detector to accumulate a line scan along the banknote at a same cross-axis location as a field of view of the excitation source. In one embodiment the step of directing includes delaying operation of the excitation source for a period of time that is a function of at least a speed of conveyance, and a distance between a illumination points of the stimulus source and the excitation source. The photonically active security feature can include at least one thread or planchette or other structure, such as a tape, having a substrate material and an electromagnetic radiation emitting and amplifying material for providing a laser-like emission. The structure can be embedded within or disposed on the banknote. The detected further emission may be an optical code for identifying at least one characteristic of the banknote.