Metallic Grating on a D-Shaped Fiber for Refractive Index Sensing

Author

Hai-Tao Yan ; Qi Liu ; Yang Ming ; Wei Luo ; Ye Chen ; Yan-qing Lu

Author_Institution

Nat. Lab. of Solid State Microstructures, Nanjing Univ., Nanjing, China

Volume

5

Issue

5

fYear

2013

fDate

Oct. 2013

Firstpage

4800706

Lastpage

4800706

Abstract

Metallic grating (MG) with high accuracy is fabricated on the side surface of a D-shaped fiber by using focused ion beam (FIB) machining. The D-shaped fiber is obtained through polishing the cladding of a single-mode fiber away from one side. Then, a thin-film layer of gold is deposited on the flat side surface. A 38- μm-long grating with the pitch of 485 nm is further milled on the gold film. The guiding mode and the surface plasmon polariton mode are thus coupled in the MG through the evanescent field for sensing applications. The refractive indexes of pure water and isopropanol are measured. A sensitivity of 917 nm/RIU is obtained.

Keywords

diffraction gratings; fibre optic sensors; focused ion beam technology; gold; metallic thin films; optical fibre fabrication; organic compounds; polaritons; polishing; refractive index measurement; refractometers; surface plasmons; water; Au; D-shaped fiber; H₂O; focused ion beam machining; gold thin-film layer; guiding mode; isopropanol; metallic grating; polishing; pure water; refractive index sensing; single-mode fiber; size 38 mum; surface plasmon polariton mode; Optical fiber couplers; Optical fiber polarization; Optical fiber sensors; Optical surface waves; Refractive index; D-shaped fiber; Metallic grating (MG); sensor;

fLanguage

English

Journal_Title

Photonics Journal, IEEE

Publisher

ieee

ISSN

1943-0655

Type

jour

DOI

10.1109/JPHOT.2013.2284244

Filename

6623191