Bradley D A, Mahdiraji G Amouzad, Ghomeishi M, Dermosesian E, Adikan F R M, Rashid H A A, Maah M J
Department of Physics, University of Surrey, Guildford GU2 7XH, UK; Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Integrated Lightwave Research Group, Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Appl Radiat Isot. 2015 Jun;100:43-9. doi: 10.1016/j.apradiso.2014.12.005. Epub 2014 Dec 6.
A method for improving the thermoluminescence (TL) yield of silica-based optical fibres is demonstrated. Using silica obtained from a single manufacturer, three forms of pure (undoped) fibre (capillary-, flat-, and photonic crystal fibre (PCF)) and two forms of Ge-doped fibre (capillary- and flat-fibre) were fabricated. The pure fibre samples were exposed to 6 and 21MeV electrons, the doped fibres to 6MV photons. The consistent observation of large TL yield enhancement is strongly suggestive of surface-strain defects generation. For 6MeV irradiations of flat-fibre and PCF, respective TL yields per unit mass of about 12.0 and 17.5 times that of the undoped capillary-fibre have been observed. Similarly, by making a Ge-doped capillary-fibre into flat-fibre, the TL response is found to increase by some 6.0 times. Thus, in addition to TL from the presence of a dopant, the increase in fused surface areas of flat-fibres and PCF is seen to be a further important source of TL. The glow-curves of the undoped fibres have been analysed by computational deconvolution. Trap centre energies have been estimated and compared for the various fibre samples. Two trap centre types observed in capillary-fibre are also observed in flat-fibre and PCF. An additional trap centre in flat-fibre and one further trap centre in PCF are observed when compared to capillary fibre. These elevated-energy trap centres are linked with strain-generated defects in the collapsed regions of the flat fibre and PCF.
本文展示了一种提高硅基光纤热释光（TL）产量的方法。使用来自单一制造商的二氧化硅，制备了三种形式的纯（未掺杂）光纤（毛细管光纤、扁平光纤和光子晶体光纤（PCF））以及两种形式的锗掺杂光纤（毛细管光纤和扁平光纤）。将纯光纤样品暴露于6和21MeV的电子下，将掺杂光纤暴露于6MV的光子下。对热释光产量大幅提高的一致观察强烈表明产生了表面应变缺陷。对于扁平光纤和光子晶体光纤的6MeV辐照，观察到每单位质量的热释光产量分别约为未掺杂毛细管光纤的12.0倍和17.5倍。同样，通过将锗掺杂的毛细管光纤制成扁平光纤，发现热释光响应增加了约6.0倍。因此，除了掺杂剂存在导致的热释光外，扁平光纤和光子晶体光纤熔合表面积的增加被视为热释光的另一个重要来源。通过计算去卷积分析了未掺杂光纤的发光曲线。估计并比较了各种光纤样品的陷阱中心能量。在毛细管光纤中观察到的两种陷阱中心类型在扁平光纤和光子晶体光纤中也有观察到。与毛细管光纤相比，在扁平光纤中观察到一个额外的陷阱中心，在光子晶体光纤中观察到另一个陷阱中心。这些高能陷阱中心与扁平光纤和光子晶体光纤塌陷区域中的应变产生缺陷有关。
