Evaluation of the performance of high phosphorous with germanium codoped multimode optical fiber for use as a radiation sensor at low dose rates

We propose a GeO2–P2O5-codoped step index multimode (SIMM) fiber having a core diameter of around 50 μm with numerical aperture of around 0.21–0.22. The proposed SIMM fiber shows excellent linear radiation response behavior with sensitivity of around 0.69–0.97 dB/m/100 rad at a 505 nm wavelength within the dose rate range of 10–100 rad/h, as well as very low recovery at room temperature using a Co60 gamma radiation source. This enables its practical application in fiber optic personal dosimeters for measurement of low dose gamma radiation.