Hardware embedded fiber sensor interrogation system using intensive digital signal processing

Abstract

- The description of an interrogation system for fiber Bragg grating sensors is reported. The full implementation in hardware of the required signal processing is proposed and made publicly available. The hardware description is implemented in a field programmable gate array (FPGA) development kit and the processing units allow one to control an optoelectronic interrogation system that uses the tunable filter method. Since the signal that drives the used Fabry-Perot filter (FFP) using a digitalto-analog converter (DAC) requires the generation of a triangular/saw-tooth waveform, the non-linear behavior of the DAC is compensated with a new methodology in this application using FPGA. When it operates controlled by a personal computer, off-board additional adaptive signal processing is used to suppress optical interference in an innovative way while removing undesired distortions in the signals caused by reflections in the optical circuit.