Singlemode optical fibre surface plasma wave chemical sensor

Author

Tubb, A.J.C. ; Payne, F.P. ; Millington, R. ; Lowe, C.R.

Author_Institution

Dept. of Eng., Cambridge Univ., UK

Volume

31

Issue

20

fYear

1995

fDate

9/28/1995 12:00:00 AM

Firstpage

1770

Lastpage

1771

Abstract

A novel singlemode optical fibre surface plasma wave sensor which operates over an extremely broad spectral range is reported. This is achieved by coating a gradually tapering singlemode fibre with a thin layer of silver ~50 nm thick on top of an adhesive layer of chromium 3 nm thick. The gradual change in the taper cross-section results in distributed phase matching between the fibre mode and the surface plasma wave, permitting a plasma wave to be excited over a spectral range from ~600 to 1000 nm. The device shows extreme sensitivity to small changes in the external refractive index, with changes in refractive index of ~5×10^-4 being detectable. The device has considerable potential as a biochemical sensor using surface immobilisation techniques

Keywords

chemical sensors; fibre optic sensors; surface plasmons; 600 to 1000 nm; Ag-Cr; adhesive chromium layer; biochemical sensor; distributed phase matching; refractive index; silver layer; single mode optical fibre surface plasma wave chemical sensor; spectral range; surface immobilisation; taper cross-section;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el:19951206

Filename

469244