In order to widen the tunable range

the PL spectra of C102 and RH6G in the ethanol solution with different concentration and in embedded films-porous alumina were studied. C102 and RH6G are good dye in the dye family

they are characterized by wide tunable range and fine physical and chemical quality. The carrier anodic porous alumina is transparent in the range of visible light and that it will not disturb the absorption of dye. Commonly

the dye with shorter wavelength absorption and emission spectrum was named as donor

and the dye with longer wavelength absorption and emission spectrum was named as acceptor. It was known that if the fluorescence spectrum of the donor overlapped with the absorption spectrum of the acceptor

the donor would deliver part of its energy to the acceptor

and the acceptor would luminescence because of excitation. Anodization was conducted at a constant voltage condition using a DC stabilized power and flow supply and the specimens were prepared and measured in the ambient air. In this experiment

C102 was donor and RH6G was acceptor. It was found that the fluorescence spectrum of C102 and the absorption spectrum of RH6G overlapped in a certain range

so if they were mixed according to a definite proportion

the spectra would be expanded comparatively to any one of these two dyes. Keeping the concentration of the donor constant and altering that of the acceptor

the author found that

along with the increasing of the acceptor's concentration

the donor's fluorescence spectra shifted to shorter wavelength (blue shift)

while the fluorescence of the acceptor shifted to longer wavelength (red shift). The trend of intensity alteration was that the intensity of donor changed from a degree far exceeding that of the acceptor to the degree almost equal to that of the acceptor and at last

the intensity of the acceptor exceeded that of the donor

when the intensity of acceptor was nearly equal to zero. All these suggested that energy transfer existed between donor and acceptor. The enhancement of acceptor PL intensity was at the cost of the weakening of donor PL intensity. Donor strengthened the efficiency of energy transfer while the concentration of acceptor increased. Compared with the fluorescence spectra in anodic porous alumina

it was found that the fluorescence spectra range of these two dye mixed together was wider evidently than that of one

and the trend of variation was similar to that in the ethanol solution. At last

the fluorescence spectra in ethanol solution and in anodic porous alumina were also compared. By this experiment

it was found that porous alumina perhaps was good medium in the development of solid tunable lasers.