Fiber optic measurement system for spatially distributed strain and temperature measurements

The availability of doped optical fibers with low attenuation induced not only a new era in the field of communication technology during the last decade, it also paved the way for completely new sensor concepts and measuring systems. The fiber phase grating written by UV laser light into the core of an optical fiber has developed to a promising component for several sensor applications. This contribution presents a photonic measurement system with Fiber Bragg Grating (FBG) sensors for a distributed temperature and strain reading. Due to the availability of high speed optoelectronic recording devices like CMOS- and CCD-detectors a significant bottleneck in the photonic metrology area is in the digital signal processing. Meeting the real time requirements, a signal processing platform with three parallel digital signal processors (DSPs) with a processing performance of 2.7 GFLOPs (Giga Floating point Operations per Second) at a clock rate of 150 MHz per DSP was developed. This processing performance enables the execution of subpixel approximation algorithms and the analysis of complex dynamic strain measurements up to 1 kHz at 36 test points.