Development of a Long Period Fiber Grating Interrogation System Using A Multimode Laser Diode

Sensors

Paulo Santos¹  Pedro Jorge¹  Luís Henrique Silva²  José Manuel Baptista²  Luís C. C. Coelho³ 

[1] Department of Physics and Astronomy, Faculty of Sciences, University of Porto, R. Campo Alegre 687, 4169-007 Porto, Portugal;Faculty of Exact Sciences and Engineering, University of Madeira, Campus da Penteada, 9020-105 Funchal, Portugal;INESC TEC—Center of Applied Photonics, R. Campo Alegre 687, 4169-007 Porto, Portugal;

关键词: interrogation technique;    laser tunability;    long period fiber grating;    multimode laser;    optical fiber sensor;   

DOI  :  10.3390/s21030749

来源: DOAJ

【 摘 要 】

Optical fiber gratings have long shown their sensing capabilities. One of the main challenges, however, is the interrogation method applied, since typical systems tend to use broadband light sources with optical spectrum analyzers, laser scanning units or CCD (Charged Coupled Device) spectrometers. The following paper presents the development of an interrogation system, which explores the temperature response of a multimode laser diode, in order to interrogate long period fiber gratings. By performing a spectral sweep along one of its rejection bands, a discrete attenuation spectrum is created. Through a curve fitting technique, the original spectrum is restored. The built unit, while presenting a substantially reduced cost compared with typical interrogation systems, is capable of interrogating along a 10 nm window with measurement errors reaching minimum values as low as 0.4 nm, regarding the grating central wavelength, and 0.4 dB for its attenuation. Given its low cost and reduced dimensions, the developed system shows potential for slow-changing field applications.

【 授权许可】

Unknown