| Author Name | Affiliation | | Bowen Gong | Department of Engineering and Transportation, South China University of Technology, Guangzhou 510640, China | | Huiying Wen | Department of Engineering and Transportation, South China University of Technology, Guangzhou 510640, China | | Hongtao Li | Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 511443, China |
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| Abstract: |
| A two-port encapsulated low-contrast grating with suppressed zeroth order under normal incidence is described in this paper. Based on such grating configuration, the improved efficiency and spectral bandwidth of the first order for TE and TM polarizations with a designed period of 1860 nm can be obtained. On the one hand, some of the accurate grating parameters were numerically optimized utilizing a rigorous coupled-wave analysis; on the other hand, the inherent physical mechanism suppressing the zeroth order through an encapsulated fused-silica grating was adequately interpreted on account of a simplified modal method. Encapsulated grating with a cover layer cannot be simply considered as adding a coating on it. Compared with reported surface-relief grating, all parameters of encapsulated grating should be re-optimized and the optimized performances of encapsulated grating were greatly improved. Therefore, the encapsulated grating can be potentially applied in writing fiber Bragg gratings. |
| Key words: encapsulated grating suppression of the zeroth order improved diffraction efficiency improved spectral bandwidth |
| DOI：10.11916/j.issn.1005-9113.20016 |
| Clc Number:O436 |
| Fund: |
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| Descriptions in Chinese: |
| 在正常入射下高效率双通道封装型低对比度消零级光栅 龚博闻1，温惠英1，李宏韬2 （1.华南理工大学 土木与交通学院, 广州 510641） （2,.暨南大学 光子技术研究院 广东省光纤传感与通信技术重点实验室，广州 511486） 中文说明：本文介绍一种在正常入射下高效双通道封装型低对比度消零级光栅。基于这种光栅结构，在被设定周期为1860 nm时可以得到1级次TE和TM偏振光的高效率和光谱带宽。一方面，使用严格耦合波理论对一些精确的光栅参数进行数值优化；另一方面，利用简化模态法对封装型消零级熔融石英光栅的内部耦合机制进行充分解释。带有覆盖层的封装型光栅不是简单增加涂层，比较于被报道的表面浮雕式光栅，封装型光栅的所有参数被重新优化并且优化性能得到很好提高。因此，封装型光栅光纤在布拉格光栅写入的应用方面具有潜力。 关键词：封装型光栅；消零级；增强衍射效率；增强光谱带宽 |
