Fiber Bragg grating sensor interrogation using chirped fiber grating-based Sagnac loop

We have investigated numerically and experimentally a fiber Bragg grating (FBG) sensor interrogation scheme utilizing a linear chirped grating-based Sagnac loop as a wavelength-dependent receiver. The scheme is suitable for both static and dynamic sensor interrogation with advantages of stable and linear readout response and easily-adjustable sensing resolution and dynamic range. Static and dynamic strain resolutions as high as ± 4.2 μ/spl epsiv/ and 0.406 μ/spl epsiv///spl radic/ Hz have been demonstrated using this scheme.