Abrupt Taper Michelson Interferometer Using Heterodyne for Measuring Refractive Index

Author

Yu-Chan Liang ; Chia-Chi Liao ; Yu-Lung Lo

Author_Institution

Dept. of Mech. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan

Volume

26

Issue

23

fYear

2014

fDate

Dec.1, 1 2014

Firstpage

2330

Lastpage

2333

Abstract

A method is proposed for measuring the refractive index (RI) of aqueous solutions using an abrupt taper Michelson interferometer and a synthetic heterodyne detection scheme. In the proposed approach, the abrupt taper Michelson interferometer is implemented with a Fabry-Perot cavity in a path-matching differential interferometer. The RI of the aqueous solution is then extracted from the phase shift of the heterodyne demodulated interferometric signal. The experimental results show that a change in the RI of 0.0001 prompts a phase shift of sim 1.35° in the demodulated signal given the use of an abrupt taper Michelson interferometer with a sensing length of 20 cm.

Keywords

Fabry-Perot interferometers; Michelson interferometers; demodulation; fibre optic sensors; heterodyne detection; optical phase shifters; optical signal detection; refractive index; refractive index measurement; Fabry-Perot cavity; abrupt taper Michelson interferometer; aqueous solutions; heterodyne demodulated interferometric signal; path-matching differential interferometer; phase shift; refractive index measurement; synthetic heterodyne detection scheme; Fabry-Perot; Optical fiber amplifiers; Optical fiber sensors; Optical interferometry; Phase shifting interferometry; Refractive index; Refractive index; abrupt taper Michelson interferometer; heterodyne modulation; path-matching differential interferometer;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2014.2355262

Filename

6892998