Author Affiliations
Abstract
1 School of Optical and Electronic Information, NGIA, Huazhong University of Science and Technology, Wuhan 430074, China
2 Shenzhen Techwinsemi Optoelectronic Co., Ltd., Shenzhen 518000, China
3 Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Shanghai Institute for Advanced Communication and Data Science, Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication, Shanghai University, Shanghai 200444, China
4 Aston Institute of Photonic Technologies, Aston University, Birmingham B4 7ET, UK
We report the observation of second order Bragg resonance (2nd-OBG) produced by tilted fiber gratings (TFGs) fabricated using phase mask UV inscription. The theoretical analysis has revealed that the generation of high order Bragg resonance of gratings is induced by a square-shape refractive index profile, which is caused by over-saturated UV exposure. In the experiment, we have studied the TFGs with different tilt angles under over-saturated UV exposure, in which all gratings have showed the 2nd-OBR, and the larger tilt angle of the grating has the stronger 2nd-OBR. When the tilt angle of the grating is , the Bragg resonance exhibits very strong polarization dependence, because the 2nd-OBR wavelength is located within the polarizing bandwidth of 45° TFG. Finally, we have demonstrated an erbium-doped fiber laser with degree of polarization, and, by applying mechanical stretching on the grating, a wavelength tunable laser output has been achieved. The output laser shows amplitude variation within 1 h continuous monitoring of the laser.
tilted fiber grating fiber laser Chinese Optics Letters
2022, 20(1): 012201
1 华中科技大学光学与电子信息学院, 湖北 武汉 430030
2 华中科技大学武汉光电国家研究中心, 湖北 武汉 430030
报道一种基于45°辐射倾斜光纤光栅(RTFG)的全光纤偏振相关器件。由于独特的偏振相关模式耦合特性,其可作为一种理想的全光纤起偏器、偏振相关耦合器、全光纤衍射器。基于体电流法建立倾斜光纤光栅的偏振耦合理论,从理论和实验角度系统地分析45° RTFG的偏振辐射耦合、衍射分光及偏振特性。仿真结果和实验结果表明,45° RTFG的透射和辐射有良好的偏振功能。一根长度为24 mm的45° RTFG在波长为1550 nm处的偏振消光比(PER)为22 dB,3 dB带宽超过300 nm。通过制备不同长度的45° RTFG,可以实现具有不同PER的光栅。光栅的辐射模沿角向呈准高斯分布,沿轴向呈指数衰减分布,并且其空间衍射角色散约为0.054 (°)/nm。实验结果与理论结果完全匹配,45° RTFG具有潜在的应用前景。
光纤光学 光纤器件 倾斜光纤光栅 光纤衍射器件 光纤偏振器件 光学学报
2020, 40(23): 2306003
