报告人：闫志君副教授

报告题目：基于45度倾斜光纤光栅全光纤器件及其应用

             45degree tilted fiber grating based in fiber devices and their applications

报告时间：2017年12月4日（周一）上午9:30

报告地点：物理与电子工程学院4楼学术报告厅

主办单位：江苏省先进激光材料与器件重点实验室、物电学院、科技处

报告人简介：

闫志君，男，华中科技大学光电学院下一代互联网接入系统国家工程实验室副教授。2003年/2006年于兰州大学分别获得凝聚态物理理学学士学位/硕士学位，2009年获得阿斯顿大学国际学生奖学金于AIPT攻读博士学位。2013年获得阿斯顿大学光子学博士学位。2012年，阿斯顿大学首位优秀海外留学生奖学金获得者。2013年-2016年英国阿斯顿大学光电子技术研究所博士后研究员。2014年，教育部春晖计划资助下前往西安光机所进行学术交流。2015年入选陕西省第七批“百人计划”人才计划。长期从事新型光纤光栅器件的设计、制备以及应用研究。先后开发多种新型光纤光栅器件，并实现传感，激光器方面应用。同时开创性的开发一种是适用于光纤陀螺仪光纤光栅器件，目前已经推广产业化。主持或参与国家自然科学基金、国防预研项目，英国创新研究计划、英国科研投资基金、欧洲航空研究发展中心、英国EPSRC以及英国JKlaser公司、美国空军实验室和波音公司合作项目等多个项目。迄今在国外一流期刊及著名国际会议上发表科技论文100篇，合著英文书籍两部，申请发明专利6项，其中4项授权（包括3项国际专利）。

Abstract— Fiber gratings are an idea in-fiber device, which have been widely applied in optical fiber laser, sensing and communication system. In this talk, we would introduce a novel tilted fiber grating structure-45° tilted fiber grating (45°-TFG) based in-fiber optical devices and their application in fiber laser , imaging and communication systems. The working principle of 45°-TFG is based on Brewster law, which can function as an ideal in-fiber linear polarizer or in-fiber diffraction grating. As the in-fiber polarizer, the polarization extinction ratio achieved by a 48mm long 45°-TFG has exhibited an exceedingly high polarization extinction ratio (PER), e.g. it achieved a PER of 50dB at the peak value and more than 40dB over 50nm wavelength range. 45°-TFGs have been fabricated and operating  at different working wavelength range from 800nm to 2400nm, almost covering the whole near infrared range. Comparing with the other in-fiber polarizers, such as anisotropic absorption overlay, chiral fiber grating, and polarizing fiber based structures, the 45°-TFG based polarizers have many advantages, including low cost, simply fabrication process, not limited by the fiber type, arbitrary operation wavelength, high PER, linear polarization state preservation and high handling power. By using its polarizing property, we have utilized the 45°-TFGs in the laser system to achieve single polarization output and mode locking short laser operation.  In addition, the 45°-TFGs were also performed as  excellent in-fiber diffraction gratings in all-fiber spectrometer, OCT system, spectra encoded imaging system and also applied in optical communication system.