矩形薄板单模光纤研磨制备及其电光调制与传感器件研究

The best method to prepare optical fiber devices is mechanical processing based on ordinary single-mode fiber (SPF) due to the demanding of low-cost and high-efficiency in industry application. Researching results published during the past several decades about side-polished fiber prove the feasibility and practicability of preparing optical fiber devices by polishing. however, there are some problems about SPF obtained by polishing, such as the distance and the poled efficiency. Such difficulties restrict the extensive application for SPF in industry. This item will develop a kind of ultrathin rectangular SMF in order to replace the SPF. And based on this kind of thin fiber, in the first place, we will develop the economic electro-optic phase modulator by using the technologies of group machining and batch pole manufacturing. And then, we will develop high sensitivity voltage sensor and low frequency vibration sensor by using the technologies of thin polymer film waveguide and analysis of thin plate construction mechanics. The research work above will fill in gaps at home and aboard in the area of preparing optical fiber devices by mechanical method. The low-cost and high-efficiency performance of this kind method for obtaining optical devices can satisfy the industry application demand, due to the usage of advanced technologies, such as group grinding and group coating. The research results of this item have important academic value and business application prospect.

基于价格低廉的普通单模光纤，利用机械加工方法制备光纤器件是低成本高效率工业应用的最佳选择。过去几十年中所报道的侧边抛磨光纤大量研究成果证实了使用机械研磨法制备全光纤器件的可行性及实用性。然而，目前使用机械研磨法制备的D型光纤在制作调制器件时存在一些问题，如电极距离、极化效率等，限制了其在工业领域的大规模应用。本项目拟开发可以有效替代D型光纤的超薄矩形单模光纤，并以此为基材，一方面结合成组加工与批量电极镀制技术、开发实用的全光纤电光相位调制器；另一方面结合多层聚合物薄膜平面波导构建技术及平板光纤基材的结构力学特性，开发高灵敏度电压传感器及低频全光纤振动传感器。上述研究工作将弥补国内外在机械研磨法制备光纤器件基材领域的空白，且其以普通单模光纤为材料，通过批量磨削、涂覆方式，所开发的调制器及传感器将完全满足低成本、高效率制造的工业推广要求。本课题的研究成果具有重要的学术价值及商业应用前景。

基于单模光纤的研磨加工方式来制造传感器基材，具有实现大批量低成本制造的潜力。本课题在国内外相关研究工作的基础上，首先基于原子力显微镜与扫描电子显微镜获得了抛磨光纤表面微纳形貌，并利用功率谱密度、小波方法、分形理论对抛光表面物理形貌进行了全面表征，获得了表面中频波纹与高频粗糙度的全部信息；其次，利于周期+幅值的正余弦模型并首次将分形理论与Maxwell-Garnet理论结合，对表面形貌中的波纹与粗糙度信息进行了光学建模，基于COMSOL数值分析方法对上述表面特征对Ag膜等离子传感器的传感特性进行了全面分析，获得了表面形貌对传感器共振波长、半高宽及灵敏度关键特性参数的影响规律；表面波纹可以引起SPR损耗峰的偏移及传感器灵敏度的改变。数值计算的最大灵敏度为5500nm/RIU. 对于精密表面，粗糙度是表面频率信息中的主要成分，在这样的表面上，共振波长以大概率发生蓝移现象。当分形维数为1.3时，最大灵敏度可达6000nm/RIU。银膜厚度在40nm-50nm间，灵敏度随膜后的变化不大。实验样品的最大实测灵敏度为5500nm/RIU。这一结果与理论计算吻合的较好。通过分析发现，3000# and 7000# 粒度的砂纸能够克服上述缺陷，非常适合快速制造SPF传感器，而不带来灵敏度的下降。这一结论对侧抛光纤SPR传感器制造具有重要的指导意义。再次，为抑制或改善Ag膜传感器的衰减红移特性，基于热蒸镀方式成功地在Ag膜表面镀制了5nm厚的金膜作为保护层，发现金-银复合膜层成功地抑制了Ag膜的快速衰减特性，延长了Ag膜传感器在空气中的存储时间。本课题的实施，为低成本大批量制造长寿命的侧抛光纤Ag膜等离子折射率传感器奠定了基础。