Plasmon enhanced generation of stimulated emission of laser dyes in pores of Al2O3

In this work, we present the results of a research of the properties of fluorescence and stimulated emission of the pyrometene 567 (PM 567) and 6-amino-1h-phenalen-1-one molecules in pores of aluminum oxide with Ag and Au... [ view full abstract ]

In this work, we present the results of a research of the properties of fluorescence and stimulated emission of the pyrometene 567 (PM 567) and 6-amino-1h-phenalen-1-one molecules in pores of aluminum oxide with Ag and Au nanoparticles. Films of porous alumina were obtained by electrochemical anodizing. Synthesis of AgNPs in the pores of Al₂O₃ was carried out by the single-jet crystallization method. Au nanoparticles in alumina pores were obtained by reduction of HAuCl₄ with alkali NaOH. It is shown that the fluorescence of the PM567 dye in porous alumina depends on the concentration of AgNPs. The maximum value of the luminescence intensity is achieved at a concentration of C_Ag = 0.42*10^-7 mol, and a further increase in C_Ag results in quenching of the fluorescence. Enhanced emission of PM567 in the pores of Al₂O₃ at C_Ag = 0.42*10^-7 mol was obtained in the short-wave maximum of the fluorescence band (Fig. 1). Comparison of the experimental data for the samples with and without AgNPs shows a correlation between changes in the radiation intensity and the half-width of the emission spectrum. For a film with AgNPs, the lasing threshold is reduced by a factor of 1.4. The effect of AgNPs on the efficiency of the generation of PM 567 molecules in pores showed that the efficiency of generation increased and amounted to 0.4%. For the 6-amino-1h-phenalen-1-one dye, the fluorescence spectrum overlaps well with the plasmon spectrum of AuNPs. The maximum intensity of the fluorescence of the dye was obtained with C_Au = 0.32*10^-6 mol. In figure 2 shows the appearance of stimulated emission (curve 2) of the dye in Al₂O₃ films with AuNPs. In the absence of NPs at the same pump power, only spontaneous emission is observed (curve 1). Stimulated emission of 6-amino-1h-phenalen-1-one molecules in the pores of aluminum oxide was obtained at the maximum of the fluorescence band. The threshold of stimulated emission was 1.7 MW/cm².