IDIL Fibres Optiques (FR)
Pixel sur Mer (FR)
Photonics Bretagne (FR)
Fiber optic sensors are used in various industrial and civil engineering sectors. These are tools for very efficient monitoring of the deformation of structures, temperature variations or the detection of other physico-chemical phenomena.
However, their deployment can sometimes be more complicated than it seems and this is often due to their main quality: their multiparametric sensitivity.
Indeed, when one wishes to use this type of technology, care must be taken to correctly decouple the influence of the various external parameters and especially when the sensor in question is integrated or in direct contact with a structure which can, itself, present a specific response to external variations.
The most classic case is that of measuring the temperature of a Bragg grating type sensor on optical fiber bonded to a metal support. The temperature variations will also induce an expansion of the support which will lead to a longitudinal stress on the fiber. The response of the sensor will therefore be affected and it will be difficult to deduce the true temperature measurement.
In some applications, this can be a real obstacle and even a blocking point in the use of this technology. When possible, we will seek to discriminate between the phenomena by multiplying the number of sensors or by using complex packaging that makes it possible to compensate or limit one or the other effect.
The CAFCA project will develop new fiber sensor approaches to intrinsically discriminate stress- and temperature-related contributions.