High temperature optical fiber sensor based on compact fattened long-period fiber gratings

• Published in: Sensors (Basel, Switzerland) Vol. 13; no. 3; pp. 3028 - 3038
• Main Authors: Mata-Chávez, Ruth I, Martínez-Rios, Alejandro, Estudillo-Ayala, Julián M, Vargas-Rodríguez, Everardo, Rojas-Laguna, Roberto, Hernández-García, Juan C, Guzmán-Chávez, Ana D, Claudio-González, David, Huerta-Mascotte, Eduardo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 04.03.2013; Molecular Diversity Preservation International (MDPI)
• Subjects: dispersion shifted fiber; electric arc; Electronic mail systems; Equipment Design; fattening; Fiber Optic Technology; High temperature; Hot Temperature; Humans; long-period fiber grating; Optical Fibers; Sensors; Spectrum allocation; temperature sensor; Mexico
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s130303028

A compact high temperature fiber sensor where the sensor head consists of a short fattened long period fiber grating (F-LPFG) of at least 2 mm in length and background loss of -5 dBm is reported. On purpose two different F-LPFGs were used to measure temperature variations, taking advantage of their broad spectrum and the slope characteristics of the erbium light source. This approach affected the spectrum gain as the linear band shifting took place. The measured sensitivity of the long period fiber gratings were about 72 pm/°C in a range from 25 to 500 °C. Here, the temperature rate of the experiment was 0.17 °C/s and the temperature response time was within 3 s. Moreover, temperature changes were detected with an InGaAs photodetector, where a sensitivity of 0.05 mV/°C was achieved.