The fiber optic surface plasmons - resonance - sensor for the determination of refractive indices of fiber of adjoining media

摘要

The present invention relates to a fiber optic surface plasmons - resonance - sensor for the determination of refractive indices of fiber of adjoining media according to the german patent no. 10 2008 046 320, containing at least one is used as an optical waveguide single-mode - fiber (3), a light source (4) and a detector (5), which is in the irradiation - and panel (26) of the single-mode - fiber (3) are located, between the fiber (3) and the light source (4) / detector (5) a fiber coupler (24) or circulator (28) is arranged to be spliced, and wherein the light at which the light source (4) facing the inlet region (6) into the fibre (3) and the fiber (3) a of the inlet area (6), in opposite directions, shaped end area (7), and further the following functional elements- a in the core region (8) of the optical fiber (3) also long periodic bragg - grid (9) - lpg - to the coupling of the initially - core mode (10) into a selected jacket mode (11),- a the surface (25) of the shell (12) of the fiber (3) completely surrounding thin jacket metal layer (13), on which the selected jacket mode (11) an upper surface plasmons shaft (14) and the excited for the coupling of the jacket mode (11) is arranged, andthe remaining optical power (i_opt) in the output - core mode (15) of the detector (5) for measuring and evaluation according to a functional dependence i_opt = f (n_A,λ) is fed to,the end region (7), both in the fiber shell (12) with a ..