Sistema embarcado para detecção e determinação da posição dos picos de bragg em FBGs

Abstract

This work developed a software to be embedded in an autonomous system based on ARM architecture, as the goal of detecting the peak position of a spectrum reflected by a Bragg grating written to optical fiber (FBG) and interrogated by the commercial Interrogator I-MON 512 E. The software was developed for the ARM architecture using the pcDuino platform which allows real-time monitoring and the data can be viewed in a graphical interface. For detecting the position of the peaks was applied to an algorithm that approximates the experimental data by a Gaussian function by the method of least squares. The system is characterized from the monitored temperature on the surface of a thermoelectric cell readings were made between 0°C and 100°C. Comparing the position of the Bragg peak registered with the system developed and the Ext_Evaluation software provided by the manufacturer of the interrogator I-MON it appears the average difference is approximately 0,010 nm. The mean difference in the position of the Bragg peak is less than 0.5 pm resolution is informed by the manufacturer of the interrogator I-MON. However, usually interested in changes in position of the Bragg peak instead of on absolute position in the spectrum. Thus, it can be concluded that the proposed algorithm is effective detecting the variation in position of Bragg peaks using FBG sensors.