Many times when a fissure in a concrete structure is discovered, it is too late because the fissure has already propagated. Because of this, a fiber optic sensor for detecting fissures at their origin was sought to be developed. The goal of developing such a sensor was to monitor the formation of fissures in their initial stages before they propagate and, in this way, avoid the failure of a structure. The functionality of such a sensor was shown and was able to detect fissures early (from their origin) in any part of the structure. This sensor is innovative due to the fact that it can monitor the condition of a structure in a distributed way and not at points. The possibility exists that, through special calibration, certain information about the deformation of structures can be obtained.