Brambilla G, Pruneri V, Reekie L, Payne D N
Opt Lett. 1999 Aug 1;24(15):1023-5. doi: 10.1364/ol.24.001023.
We report a novel method to increase the UV photosensitivity of GeO(2): SiO(2) optical fibers based on exposure to CO(2) laser irradiation before grating writing. Fibers treated with a CO(2) laser can produce gratings with refractive-index modulation two times greater and a Bragg wavelength that can be 2 nm longer than those of untreated fibers. Experiments on GeO(2): SiO(2) preform samples treated with a CO(2) laser in a way similar to the fibers showed a marked increase of the 242-nm absorption band, which is associated with an increase of germanium oxygen-deficient centers and is believed to be responsible for the higher photorefractive response.
我们报道了一种基于在写入光栅之前对GeO(2):SiO(2)光纤进行CO(2)激光辐照来提高其紫外光敏性的新方法。用CO(2)激光处理过的光纤所产生的光栅，其折射率调制比未处理的光纤大两倍，且布拉格波长比未处理的光纤长2 nm。对以类似于光纤的方式用CO(2)激光处理过的GeO(2):SiO(2)预制棒样品进行的实验表明，242 nm吸收带显著增加，这与锗氧缺陷中心的增加有关，并且据信这是导致更高光折变响应的原因。
