Application of laser-induced fluorescence spectrometry to the inspection of timbers

Whenever the fluorescent substances hit by a laser beam,the molecules absorb the energy,then jump from the lowest orbit to another provocation orbit.Because the provocation condition is so instable that the molecules then come back to the lowest orbit,glowing fluo-rescence.The distribution of the fluorescence spectrum,the peak intensity of the spectrum and its situation can make a clear distinction between different substances.By analyzing pines,elms and alamos,the common features of the fluorescence spectra of these timbers are obtained,as well as their individual features,which will be the basis of distinguishing different species of trees.