LIBS Efficiency Increase via Plasmonic Nanoparticles in the Study of Synthetic Opal Matrices

In this article, a method of depositing plasmonic particles on synthetic opal matrices was used for increasing the efficiency of laser-induced breakdown spectroscopy. The fundamental radiation, second and third harmonics of a picosecond neodymium laser were used to generate plasma. The dependences of the gain factor on the size of the laser spot, as well as on the concentration of silver particles, were obtained. The maximum signal amplification exceeding an order of magnitude was achieved at a wavelength of 1064 nm, corresponding to the localization of the plasmon resonance mode in the gap between closely spaced particles. Emission stability when using particles also increases at all laser wavelengths used. Conducted computer simulation confirmed the results of the experiment. High sensitivity of the method allows its use for monitoring even a small amount of impurity elements and their dynamics during the synthesis of photonic crystals, as well as the dynamics of the process of filling them with various materials during infiltration.