【作者】 刘佩坤； 李彦； 魏勇； 张羽； 朱宗达；

【Author】 LIU Pei-kun;LI Yan;WEI Yong;ZHANG Yu;ZHU Zong-da;College of Science,Harbin Engineering University;

【机构】 哈尔滨工程大学理学院；

【摘要】 提出了用等离子溅射仪镀制50nm金膜的方法。针对于多模光纤表面等离子体共振（SPR）模式混合灵敏度低,难以仿真的问题,提出一种单模光纤劈尖结构SPR传感探针。研究了等离子溅射仪真空度、电流、距离、时间等参数对成膜质量及膜厚的影响,用轮廓仪标定膜厚并通过改装空间棱镜式SPR测量系统研究膜厚对SPR激励现象的影响。利用光纤研磨技术将630nm单模光纤磨制成劈尖结构并在劈尖斜面上镀制50nm金膜,在单模光纤上实现了Kretchmann棱镜结构。在显微镜下将纤芯直径为105μm的多模光纤端面对准单模劈尖的全反射光束并固定,收集SPR反射光,用于研究单模劈尖结构SPR折射率传感特性。实验结果表明:当等离子溅射仪真空度稳定在2×10^-1Pa、电流为5mA、溅射距离为1cm、溅射时间为3.5 min时,金膜镀制质量良好,膜厚为（50±5）nm。当研磨角为15°时,单模光纤劈尖SPR传感器对折射率为1.333¹.385的液体响应灵敏,共振谷可在693⁹24nm工作,平均灵敏度达4 442nm/RIU。本文提出的离子溅射仪镀制50nm金膜方法成膜质量好,膜厚满足SPR实验要求,设计制作的单模光纤劈尖结构SPR探针制作简单,灵敏度高。更多还原

【Abstract】 A method to coat a 50 nm golden film with a plasma sputtering apparatus was proposed.By considering low sensitivity on Surface Plasmon Resonance（SPR）mode mixing of multimode fibers and simulation difficulty,a SPR sensing probe of single mode fiber with the wedge structure was introduced experimentally.Firstly,the effects of parameters such as vacuum degree,electric current,distance and time on film properties and film depths were studied.The film thickness was calibrated by a profilometer and the effect of film thickness on SPR exciting phenomenon was measured by a modified SPR measurement system with a space prism.The 630 nm single mode fiber was polished into a wedge structure by fiber grinding technology,and the 50 nm golden film was coated on the inclined plane of the wedge to realize the Kretchmann prism structure on the single mode fiber.Under a micro-scope,the end face of multi-mode fiber with 105μm diameter of fiber core was directed at a total reflection beam and fixed to collect the reflection light of SPR,where the sensing property and reflective index of SPR single mode fiber with the wedge structure were studied.The results show that the golden film is well coated with（50±5）nm film thickness under the conditions of 2×10^-1 Pa vacuum degree,5mA electric current,1cm sputtering distance and 3.5min sputtering time.When grinding angel is 15°,the SPR sensor of single mode fiber with wedge structure is sensitive to liquid with refractive index between 1.333 and 1.385 and the working range of resonance valley is between 693 nm and 924 nm with the mean sensitivity of 4 442nm/RIU.The proposed ion sputtering equipment meets the demand of SPR experiment and the SPR probe of single mode fiber with wedge construct is characterized by high sensitivity,simple procedures and great application potential.更多还原