Next Article in Journal
Next Article in Special Issue
Previous Article in Journal
Sensors 2013, 13(4), 4067-4087; doi:10.3390/s130404067
Article

Fabrication Quality Analysis of a Fiber Optic Refractive Index Sensor Created by CO2 Laser Machining

1
, 2
, 1
 and 2,*
Received: 28 December 2012; in revised form: 14 March 2013 / Accepted: 22 March 2013 / Published: 26 March 2013
(This article belongs to the Special Issue Optomechatronics)
View Full-Text   |   Download PDF [721 KB, updated 21 June 2014; original version uploaded 21 June 2014]
Abstract: This study investigates the CO2 laser-stripped partial cladding of silica-based optic fibers with a core diameter of 400 μm, which enables them to sense the refractive index of the surrounding environment. However, inappropriate treatments during the machining process can generate a number of defects in the optic fiber sensors. Therefore, the quality of optic fiber sensors fabricated using CO2 laser machining must be analyzed. The results show that analysis of the fiber core size after machining can provide preliminary defect detection, and qualitative analysis of the optical transmission defects can be used to identify imperfections that are difficult to observe through size analysis. To more precisely and quantitatively detect fabrication defects, we included a tensile test and numerical aperture measurements in this study. After a series of quality inspections, we proposed improvements to the existing CO2 laser machining parameters, namely, a vertical scanning pathway, 4 W of power, and a feed rate of 9.45 cm/s. Using these improved parameters, we created optical fiber sensors with a core diameter of approximately 400 μm, no obvious optical transmission defects, a numerical aperture of 0.52 ± 0.019, a 0.886 Weibull modulus, and a 1.186 Weibull-shaped parameter. Finally, we used the optical fiber sensor fabricated using the improved parameters to measure the refractive indices of various solutions. The results show that a refractive-index resolution of 1.8 × 10−4 RIU (linear fitting R2 = 0.954) was achieved for sucrose solutions with refractive indices ranging between 1.333 and 1.383. We also adopted the particle plasmon resonance sensing scheme using the fabricated optical fibers. The results provided additional information, specifically, a superior sensor resolution of 5.73 × 10−5 RIU, and greater linearity at R2 = 0.999.
Keywords: CO2 laser machining; optical fiber sensor; refractive index sensing CO2 laser machining; optical fiber sensor; refractive index sensing
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Chen, C.-H.; Yeh, B.-K.; Tang, J.-L.; Wu, W.-T. Fabrication Quality Analysis of a Fiber Optic Refractive Index Sensor Created by CO2 Laser Machining. Sensors 2013, 13, 4067-4087.

AMA Style

Chen C-H, Yeh B-K, Tang J-L, Wu W-T. Fabrication Quality Analysis of a Fiber Optic Refractive Index Sensor Created by CO2 Laser Machining. Sensors. 2013; 13(4):4067-4087.

Chicago/Turabian Style

Chen, Chien-Hsing; Yeh, Bo-Kuan; Tang, Jaw-Luen; Wu, Wei-Te. 2013. "Fabrication Quality Analysis of a Fiber Optic Refractive Index Sensor Created by CO2 Laser Machining." Sensors 13, no. 4: 4067-4087.


Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert