Near-field coupling of silver nanoparticle and silver islands on metal-enhanced fluorescence

This thesis studies for the plasmon-enhanced local field around multiple adjacent silver islands (SIs). The coupling plasmonic effect of the SIs enhance the near electromagnetic (EM) field within the gap zone, and at the top of SIs to increase a silver nanoparticle (SNP) to investigate the metal enhanced fluorescence (MEF). Maxwell electromagnetic theory together with the multiple multipole method are used to compute the induced EM field of the gap zone. This thesis use quantitative research method to analyze the effects of plasmon-enhanced local field with amount of SIs, the incident angles of plane wave, permutation of SIs, and different gaps of SIs. Finally, this thesis researches the MEF by changing the SNP horizontal position. Numerical results show that an extra peak at wavelength 600 nm ~ 750 nm is observed in the scattering of the efficiency as the number of silver islands increase. This peak can be interpreted as coupling effect between silver islands. When a plane wave incident angle , the coupling chain effect of silver islands is strong. The effect of silver nanoparticle significantly improve the intensity of excitation rate, phenomenon of the excitation rate is led by the position of fluorescent molecule and the amount of silver islands.