Optical refractometer based on multimode interference in a pure silica tube

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Luis Coelho (Author) Other; Jens Kobelke (Author) Other; Kay Schuster (Author) Other; Jose L Santos (Author) FCUP; Orlando Frazao (Author) FCUP

Journal

Title: Optical Engineering

Vol. 50

Final page: 100504

ISSN: 0091-3286

Publisher: SPIE

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 6 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-002-KSD

DOI: 10.1117/1.3646393

Abstract (EN): A multimode interferometer based-fiber optic sensor with a silica tube section aimed to measure refractive index (RI) variations of surrounding liquids is presented. The sensing head is a silica tube section fusion spliced to single mode fibers operating in transmission. In the splice regions tapers were made to allow the light to be guided in the silica tube while the core is formed by air. This configuration permits measurements of refractive index variations with sensitivities of 101.1, 106.29, and 107.97 nm/RIU considering resonances with different wavelengths. The same resonances were tested with temperature variations with sensitivities achieved of 7.8, 8.7, and 9.3 pm/ degrees C, respectively. The spectral variation associated with one degree temperature change corresponds to a refractive index change of similar to 8 x 10(-5), proving the low temperature dependence compared with sensitivity to RI variations. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3646393]

Language: English

Type (Professor's evaluation): Scientific