Distributed fiber optics strain sensors: from long to short distance

Developed for more than forty years, optical fibers have features that make them particularly attractive for making sensors. One of the strengths of these sensors is that they can measure different physical parameters in a distributed manner over a wide range of lengths (from a few cm up to tens of kilometers) with a spatial resolution ranging from millimeters to meters. In this article, we are particularly interested in distributed fiber sensors, mainly based on light scattering processes, for measuring strain variations. This review concerns both applications requiring long lengths of fiber in a geological context, as well as those using length less than one meter for the medical sector. While distributed fiber optics sensors have already shown their great potential for long-range applications, short-range applications are a niche sector emerging in the last few years.