全光纤化CTD温盐增敏及长期稳定性研究

Optic fiber sensor technique has many advantages in the ocean monitoring, including intrinsic insulation, high sensitivity, low-cost, easily assembled array and net, in situ real-time measurement and none power dissipation at wet-end. Researchers have performed a large number of researches and studies at home and abroad. Our group focusing on the measurement of conductivity, temperature and depth (CTD) based on optic fiber grating had got the stage achievement. The out-side comparative real-time experiment in Qingdao and the third-party participated metering test reveal that the precision of temperature is 0.01℃ and the pressure accuracy is better than 0.1%, both of them overtake the secondary standard of GB/T23246-2009, moreover, close to the primary standard, and the precision of salinity in laboratory has reached 708 pm/1% closely to the secondary standard..In order to satisfy the requirement of the primary national standard, our group will conduct the research and the study of enhancement of sensitivity of temperature and salinity of the core component, the long period grating (LPG), and the long term stability of the LPG sensor immersed in water:1) based on the metal shielded layer the technique of package and sensitivity enhancement of the LPG temperature sensor; 2) to study and come up with a new surface core LPG salinity sensor;3) to first discover and establish the re-aging model of LPG in water and to calculate the long term stability of LPG immersed in water and to improve it..These issues above mentioned are still published infrequently yet. Combining with miniaturization and self-contained refit of demodulation equipment, we will conduct more than twice comparative real-time experiment on the sea to establish the stable foundation of improving the low cost, practicability and multiform all-optic-fiber CTD that accord with the primary national standard as soon as possible.

光纤传感技术在海洋监测中有本征绝缘、灵敏度高、成本低廉、组网成阵方便、原位实时测量、湿端无电无功耗等优势，国内外已开展大量研究工作。课题组在光纤光栅温盐深(CTD)研究工作取得阶段性成果，青岛外场比对实测和第三方计量测试表明温度精度为0.01℃,压力精度优于0.1%，均超GB/T23246-2009二级、接近一级标准，盐度实验室测试达708pm/1%,接近二级。 .为达到国标一级要求，拟开展核心元器件长周期光纤光栅（LPG）的温度、盐度增敏及水中浸泡时的长期稳定性研究：1)基于金属屏蔽层的LPG温度传感器增敏及封装技术；2)提出并研究新型基于表面芯的LPG盐度传感器；3)首次发现并建立LPG水中"再老化"模型，推算并改进其长期稳定性。.上述工作鲜见报道，结合解调装备小型化、自容式改装，进行2次以上海上比对实测，为尽早开发出符合一级标准的低成本、实用化、多形式的全光纤CTD奠定基础。

海洋科学中温度盐度深度是海水的三大静态要素，光纤传感技术在海洋监测中有电绝缘、体积小、原位实时测量等优势，国内外已开展大量研究工作，课题组也就全光纤化CTD做了许多实验标定和海试工作。. 目前铠装后的温度传感器在海试中与标准SBE比测，标准差为0.01198℃，响应时间仅为48.6ms，比传统光纤温度传感器小一个数量级，性能稳定且优越。压力传感器在海试中与亚力克比对，达到了同步变化，两者误差小于0.1m。两者的海试都采取了拖曳阵形式，可实现连续测量。对于盐度传感器课题组选择了在超细光纤上制作光栅的方案，实验标定中灵敏度约为普通光纤制作的LPG的3倍。课题组重新搭建了解调系统，制作了第四代解调仪样机。与美国MOI-SM125比测中，样机各项指标明显优于后者，这表明了自研设备在核心指标上达到了国际领先的水平。. 依托本项目，课题组发表了包括SCI/EI在内的9篇文章，申请专利7项，主要培养了4位研究生。此外，课题组还获得了中国科学院战略性先导科技专项的支持。