| Autor: |
Silva S; Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas–UNICAMP, Campinas, São Paulo, Brazil., Pachon EG, Franco MA, Hayashi JG, Malcata FX, Frazão O, Jorge P, Cordeiro CM |
| Jazyk: |
angličtina |
| Zdroj: |
Applied optics [Appl Opt] 2012 Jun 01; Vol. 51 (16), pp. 3236-42. |
| DOI: |
10.1364/AO.51.003236 |
| Abstrakt: |
The proposed sensing device relies on the self-imaging effect that occurs in a pure silica multimode fiber (coreless MMF) section of a single-mode-multimode-single-mode (SMS)-based fiber structure. The influence of the coreless-MMF diameter on the external refractive index (RI) variation permitted the sensing head with the lowest MMF diameter (i.e., 55 μm) to exhibit the maximum sensitivity (2800 nm/RIU). This approach also implied an ultrahigh sensitivity of this fiber device to temperature variations in the liquid RI of 1.43: a maximum sensitivity of -1880 pm/°C was indeed attained. Therefore, the results produced were over 100-fold those of the typical value of approximately 13 pm/°C achieved in air using a similar device. Numerical analysis of an evanescent wave absorption sensor was performed, in order to extend the range of liquids with a detectable RI to above 1.43. The suggested model is an SMS fiber device where a polymer coating, with an RI as low as 1.3, is deposited over the coreless MMF; numerical results are presented pertaining to several polymer thicknesses in terms of external RI variation. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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