Ultraviolet radiation (UVR) dosimetry system and the use of Ge-doped silica optical fibres

•TL characterisation of Ge-doped SiO2 optical fibres due to UVR was reported for the first time.•Ge-doped SiO2 optical fibres showed simple glow curve, good reproducibility and high sensitivity.•Increasing of dopant concentrations can enhance the TL efficiency well.•Ge-doped SiO2 optical fibres produce a linear dose response when irradiated to UVA.

Previous studies have shown that over exposure to ultraviolet radiation (UVR), either from sunlight or artificial sources, can cause severe biological effects including cataracts, photokeratitis and skin cancer. In this respect, there exists the need to introduce a sensitive UV dosimetric material capable of measuring radiation dose to high accuracy in order to deliver UVR safely and efficiently. Present study has focussed on the investigation of the potential thermoluminescent (TL) sensitivity of commercially available germanium (Ge)-doped silica (SiO2) optical fibres subjected to UVR. The main interest of this study is to find out whether these doped SiO2 optical fibres can be used as a sensible integrator of environmental UV exposures. In the present study, commercially available Ge-doped SiO2 optical fibres have been used with a core diameter of 11 µm (CorActive, Canada), 23 µm (Central Glass and Ceramic Research Institute Kolkata, India) and 50 µm (Central Glass and Ceramic Research Institute Kolkata, India) and a cladding diameter of 125±0.1 µm, irradiated over a wide range of UV dose. Results have shown that these fibres exhibit a linear dose response (with correlation coefficient better than 0.9852). The 50 µm fibre produces greater TL response than that obtained for 11- and 23 µm fibres. The TL results are compared with that of the well-established TL dosimeter material lithium fluoride.