Usage of fiber optics as an underground deployable radon gas detector

Radon gas was previously presented to be a good tool as a proxy for pre-seismic precursory before earthquakes, especially when the detector is deployed a few meters underground in regions of high seismic activity. In this paper, we present a fiber optic-based detector that can be deployed underground and assist in the measurement of radon gas temporal concentration variations. The sensitivity of the fiber-based sensor is enhanced due to Fabry-Perot resonator realized within the fiber. The sensing principle is related to the impact of the alpha particles released from the surrounding radon gas on the optical transmission parameters of the fiber. By incorporation of WDM filters along the fiber sensor, the dispersion of the radon's radiation damage along the deployed fiber can be allocated.