The energy transfer in a proper mixture of dyes is now established as an effective mechanism of extending the wavelength region of lasing and of achieving more efficient conversion of pump light by an organic dye which alone has only small absorption at a particular pump laser wavelength (for example 337.1nm nitrogen line).It has been reported in literature that attempts made to lase safranin-T using nitrogen laser without a donor were unsuccessful

and accordingly Rho-damine6G/Safranin-T dys mixture is proposed to lase the latter.As is known that Coumarin 440 is a laser dye which strongly absorbs the 337.1nm radiation from the nitrogen laser.If an intermediary dye could be found to couple Coumarin 440 and Safranin-T spectrally

then an ternary energy transfer laser dye system might be formed. Motivated by this intention

we have investigated on the Coumarin 440/Fluorescein scdium/Safranin-T(C440/F1.Na/Saf.-T) dye mixture system. Since there are good overlaps between the fluorescence of C440 and the absorption of F1.Na and between the fluorescence of Fl.Na and the absorption of Saf.-T

and in the mean time the fluorescence quantum yields of these dyes are all reasonably high

we can predict an efficient energy transfer of the excitation from C440 cascading through Fl.Na to Saf.-T.