Index of refraction variation and photoluminescence quenching in silver-ion-exchanged glasses, due to interaction with low-energy He⁺ beam

In the present work, interaction of a low-energy (~ 40 keV) He⁺ ion beam with silver-ion-exchanged glasses is studied. It is found that the interaction leads to increase of index of refraction and optical density of the interaction area of the samples, and at the same time, results in quenching of luminescence radiation of the interacted area on the samples. A remarkable dispersion for the index of refraction (n = n(λ)) is observed. Maximum change in the index of refraction occurs for the wavelength very close to the wavelength of the red-shifted surface plasmon resonance of the silver nanoclusters embedded in the glass matrix. Photoluminescence spectra studies show that interaction of silver-ion-exchanged glasses with low-energy He⁺ beam results in reduction of ionic silver clusters to the neutral ones, which is accompanied with increase of the index of refraction. That is, the produced neutral silver nanoparticles increase the index of refraction of the interacted area on the samples. Such manipulation of the index of refraction has potential for manufacturing miniaturized phase optical diffractive elements.