Research On Anti-radiation Darkening Performance Of Multi-component Glass

Multi-component glass is an important laser glass,which are very attractive fiber matrix materials for fiber lasers due to their excellent optical and physical and chemical properties,such as lower melting temperature,higher solubility of rare earth ions,good infrared transmittance and wide tunable bandwidth.However,when glass fiber lasers are used in the environment of strong laser output or high-energy particles（such as gamma rays）in space,it will cause structural defects（called color center defects）in the glass fiber,that is,which will increase the optical absorption loss of the fiber.It will reduce the performance of the fiber laser and makes the laser ineffective in severe cases.The darkening of fiber caused by gamma rays is called radiation darkening.Due to the complexity of the structure of multi-component glass,the mechanism of radiation darkening needs to be fully understood at present,and measures to suppress the radiation darkening of multi-component glass fibers need to be systematically studied.In this paper,multi-component germanate（BGG）glass,multi-component phosphate（PKBE）glass and multi-component tellurite（TTZ）glass applied in near-infrared fiber lasers are used as the research objects,and the effect of variable valence ion doping on the anti-radiation darkening performance of these three multi-component glasses is studied.The research content and results are as follows:（1）The effect of variable valence ions(Nb⁵⁺,Ce⁴⁺and Sb³⁺)doping on the anti-radiation darkening performance of BGG glass was studied.Studies have shown that these three variable valence ions can inhibit the formation of the two color center defects of Ge-NBOHC and GEC through their own valence state conversion,thereby improving the anti-radiation darkening performance of BGG glass.Among them,BGG glass doped with Ce⁴⁺has the best anti-radiation darkening performance.（2）The effect of Ce⁴⁺and Sb³⁺doping on the anti-radiation darkening performance of PKBE glass was studied by absorption spectrum and EPR spectrum.The results show that PKBE glass doped with Ce⁴⁺and Sb³⁺can inhibit the formation of the two color center defects of POHC and POECs through its own valence transition.Among them,PKBE glass doped with Ce⁴⁺has better anti-radiation darkening performance.（3）Combined with the absorption spectrum,the influence of different cumulative doses of gamma rays on the darkening effect of TTZ glass was explored.The results showed that the absorption loss ofγ-ray irradiated TTZ glass was mainly in the ultraviolet-visible region,and TTZ glass was more sensitive toγ-rays.The darkening effect was saturated under the irradiation ofγ-rays with a dose of 20 KGy.（4）Combining absorption spectrum and EPR spectrum,the influence of variable valence ions(Nb⁵⁺,Ce⁴⁺and Sb³⁺)doping on the anti-darkening performance of TTZ glass was studied.Studies had found that undoped TTZ glass would produce two color center defects of NBOHC and Te EC afterγ-ray irradiation;TTZ glass doped with Ce⁴⁺could inhibit the generation of these two color center defects through its own valence state conversion;and TTZ glass doped with Nb⁵⁺and Sb³⁺changed the glass network structure due to the presence of Nb⁵⁺and Sb³⁺,generating more non-bridging oxygen atoms,which was easier to induce the formation of color center defects.