Enhancement of Electric and Magnetic Emission in Langmuir Blodgett Films and Sandwich Structures with Eu³⁺ Ions

Plasmonic structures provide possibilities to control and enhance spontaneous emission, including emission, at weak magnetic transitions, which is of interest for various applications. However, quenching in metal via near field excitations may present significant problems. In our work, we compare systems with dense and dilute arrangement of emitters, and experimentally study efficiency of emission and radiation patterns of electric and magnetic emitters in close vicinity of plasmonic films, gratings and inside sandwich-like structures. We show that monolayer or multilayer Langmuir Blodgett films of closely packed EuTTA molecules deposited on metal demonstrate reduced quenching and significantly enhanced excitation of surface plasmon polaritons in comparison with films where Eu ions are diluted. The results are discussed taking into account modifications of near field effects.