Sensitivity Improvement of an LPG-based Fiber Optic Humidity Sensor

Fiber optic sensors for determination of relative humidity are today a highly competitive option compared to conventional sensing technologies. This is due to the unique characteristics that highlight them such as their fast response time, their electromagnetic immunity and their small size, among others. This paper presents the results of a very simple sensitivity improvement process applied to a fiber optic humidity sensor based on the use of a Long Period Grating (LPG). Experience and knowledge generated in this work provide the basis for the further development of optical humidity sensors that will be applied in the measurement of this parameter in concrete, since water acts as a means of transporting deleterious agents in cement based materials.