Analytical Modelling of a Refractive Index Sensor Based on an Intrinsic Micro Fabry-Perot Interferometer

Sensors

Everardo Vargas-Rodriguez¹  Ana D. Guzman-Chavez¹  Martin Cano-Contreras¹  Eloisa Gallegos-Arellano¹  Daniel Jauregui-Vazquez²  Juan C. Hernández-Garc໚²  Julian M. Estudillo-Ayala²  Roberto Rojas-Laguna² 

[1] Departamento de Estudios Multidisciplinarios, División de Ingenierías, Universidad de Guanajuato, Av. Universidad s/n, Col. Yacatitas, Yuriria, Gto., C.P. 38940, Mexico; E-Mails:;Departamento de Electrónica, División de Ingenierías, Universidad de Guanajuato, Carretera Salamanca-Valle de Santiago km 3.5 + 1.8, Comunidad de Palo Blanco, Salamanca, Gto., C.P. 36885, Mexico; E-Mails:

关键词: Fabry-Perot interferometer;    fiber optics sensors;    interferometry;    non dispersive sensing;    tunable laser spectroscopy;   

DOI  :  10.3390/s151026128

来源: mdpi

【 摘 要 】

In this work a refractive index sensor based on a combination of the non-dispersive sensing (NDS) and the Tunable Laser Spectroscopy (TLS) principles is presented. Here, in order to have one reference and one measurement channel a single-beam dual-path configuration is used for implementing the NDS principle. These channels are monitored with a couple of identical optical detectors which are correlated to calculate the overall sensor response, called here the depth of modulation. It is shown that this is useful to minimize drifting errors due to source power variations. Furthermore, a comprehensive analysis of a refractive index sensing setup, based on an intrinsic micro Fabry-Perot Interferometer (FPI) is described. Here, the changes over the FPI pattern as the exit refractive index is varied are analytically modelled by using the characteristic matrix method. Additionally, our simulated results are supported by experimental measurements which are also provided. Finally it is shown that by using this principle a simple refractive index sensor with a resolution in the order of 2.15 × 10⁻⁴ RIU can be implemented by using a couple of standard and low cost photodetectors.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.