RESUMEN

We demonstrate surface plasmon resonance (SPR) fiber devices based upon ultraviolet inscription of a grating-type structure into both single-layered and multilayered thin films deposited on the flat side of a lapped D-shaped fiber. The single-layered devices were fabricated from germanium, while the multilayered ones comprised layers of germanium, silica, and silver. Some of the devices operated in air with high coupling efficiency in excess of 40 dB and an estimated index sensitivity of Delta lambda/Delta n=90 nm from 1 to 1.15 index range, while others provided an index sensitivity of Delta lambda/Delta n=6790 nm for refractive indices from 1.33 to 1.37.

Asunto(s)

Fibras Ópticas , Resonancia por Plasmón de Superficie/instrumentación , Diseño de Equipo , Germanio/química , Modelos Estadísticos , Óptica y Fotónica , Refractometría , Reproducibilidad de los Resultados , Dióxido de Silicio/química , Plata/química , Resonancia por Plasmón de Superficie/métodos , Rayos Ultravioleta

RESUMEN

Electron spin resonance spectra have been studied in partially crystallized films of La(1-x)Na(x)MnO(3) (x = 0.16) in the vicinity of the para- to ferromagnetic transition. The objects of investigation were obtained by magnetron sputtering on polycrystalline Al(2)O(3) substrates held at different temperatures. It is shown that, in a regime where the paramagnetic and ferromagnetic phases coexist, the resonance conditions for one phase strongly depend on the parameters of the other phase. As a result, the resonance field of the paramagnetic phase becomes dependent on the shape of the sample, the saturation magnetization and the fraction of the ferromagnetic phase. A simple model is developed to predict the character of the changes in the resonance field of the paramagnetic phase upon the nucleation of the ferromagnetic phase.