Passive fiber optic temperature sensor for safety applications

Fiber optic sensors (FOS) are insensitive to external EM fields and are intrinsically safe (as no electrical power is needed at the sensing point), so the measurement can be performed in areas where standard electronic devices cannot easily be applied. What is more, due to the very low silica fiber attenuation the measurement point can be located kilometers away from a light source and detector, which makes the sensors independent of a local power source. Furthermore the FOS are small so they can be used for sensing in mechanical mechanisms where there is not much free space. They can also be easily integrated with the structure of different materials for military applications (e.g. in tanks and airplanes). In this work we propose an intrinsically safe temperature sensor based on fiber optic technology. The presented sensor is entirely passive and benefits from all of the advantages mentioned above, which allows it to be applied in the most demanding environments. The construction of the presented sensor is based on a dedicated microstructured optical fiber which allows both the range and sensitivity of the sensor to be adjusted to a specific application.