An overview on high-resolution and fast interrogation spur straps of optical-fiber sensors relying on laser reflection spectroscopy is given.Fiber Bragg-gratings (FBGs) and FBG resonators built in fibers of different types are used for strain, temperature and acceleration measurements using heterodyne-detection and optical frequency-locking techniques.Silica fiber-ring RCD Safety Switch cavities are used for chemical sensing based on evanescent-wave spectroscopy.
Various arrangements for signal recovery and noise reduction, as an extension of most typical spectroscopic techniques, are illustrated and results on detection performances are presented.