A Temperature-Independent Interrogation Technique for FBG Sensors Using Monolithic Multilayer Piezoelectric Actuators

作者：Dante Alex^*; Bacurau Rodrigo Moreira; Spengler Anderson Wedderhoff; Ferreira Elnatan Chagas; Dias Jose Antonio Siqueira

来源：IEEE Transactions on Instrumentation and Measurement, 2016, 65(11): 2476-2484.

DOI：10.1109/TIM.2016.2594021

• Bragg gratings
• current measurement
• fiber gratings
• fiber optics
• optical fiber sensors
• piezoelectric actuators
• voltage measurement

In this paper, a temperature-independent technique for measurements of ac signals, such as voltage and electrical current, with fiber Bragg grating (FBG) sensors is presented. This technique is based on a twin-grating scheme, in which the measured quantity is obtained from the optical power of convolution between a sensing FBG and a tunable FBG. The proposed interrogator employs a low-voltage monolithic multilayer piezoelectric actuator (MMPA) to sweep the tunable FBG over the wavelength range of the sensing FBG, in order to obtain the convolution function accurately. A dedicated microcontrolled optoelectronic system with a firmware-based tracking routine is responsible for keeping the tunable FBG following the sensing FBG over temperature-induced wavelength shifts with subpicometric resolution, while the dc level of convolution is controlled precisely at the highest sensitivity point of operation. The MMPA employed allows the tracking of the tunable FBG after the sensing FBG over a maximum temperature difference that ranges from -29 degrees C to +90 degrees C. The proposed interrogator presents lower cost compared with the systems that employ frequency-scanning devices, such as high-speed Fabry-Perot tunable filters.

• 出版日期2016-11