Experimental proof of modification and quenching of fluorescence in polymer films

The development of synthetic dyes in great variety on the one hand and of new polymer materials by chemical process on the other hand has enlarged the range of such activities very much. In fact these polymers act as host materials where dyes of suitable amount are doped. In the present experiment we have used Ar+ laser (500 mW) for exciting the fluorescence of the sample. The exciting radiations were 4880 angstrom (blue) and 5145 angstrom (green). The salient feature of the experiment is that the laser radiation is allowed to fall on the sample and fluorescence is observed in the same direction. In the present experiment we have obtained evidence of quenching of fluorescence when excited with the help of Ar+ laser. In one specific example of polymer of polyvinyl type the 1(st) positive band system of N-2 is dramatically narrowed down. This quenching is of particular importance because modification of spontaneous emission via quantum interference has also been considered as a research topic in quantum optics.