摘要
本文利用振幅掩模的傅里叶变换法在LiNbO3∶Fe晶体中制作了一维光子晶格,通过连续旋转晶体,由功率探测器测得透射率,绘出Bragg带隙曲线。分析了用两孔振幅掩模制作的光子晶格的带宽、位置,讨论了在孔间距为6mm条件下,振幅掩模孔的数目由3个增加到5个的带隙情况,由实验观察发现了奇特的现象:衍射光的数目由2个增加到4个。从而使一个Bragg衍射角增加为多个Bragg衍射角,提高了非平行光的Bragg衍射效率。但这些衍射光是角分立的,如果能使这些衍射光成为角连续的,则能从根本上增大Bragg带宽,大大提高了光子晶体光纤的导光能力。基于这种思想,我们利用孔间距为2mm的4孔振幅掩模实现了带隙增宽的目的,为增大带宽提供了一个行之有效的办法,对光能的利用率的提高有着极其重要的作用。
Using method of amplitude mask＇s the Fourier transform, one-dimensional photonic lattice was produced in LiNbO3： Fe crystal, measured transmission efficiency useing the power detector by continuous rotating crystal , and band gap curve was plotted. Bandwidth and location of the photonic lattice made by the method of two-hole amplitude mask were analysed, band-gap situation which the number of amplitude mask holes increased from three to five under the hole spacing of 6mm was discussed. A peculiar experimental phenomena were found： The number of diffraction reached from 2 to 4, so that the bragg diffraction angle changed from single to be quite a few, which improved the bragg diffraction efficiency of the non-parallel light. However, the diffraction is angle separation, bragg band-gap will be fundamentally broadened if the diffraction become angle continuity, which will greatly improve guiding light ability of the photonic crystal fiber. Based on this idea, we realized the widened band gap , using amplitude mask with the 4 holes and 2mm hole spacing. It provides an effective way for increaseing the bandwidth. What＇s more,it plays an very important role in promoting the light energy utilization.
出处
《信息记录材料》
2011年第1期14-18,共5页
Information Recording Materials
基金
国家自然科学基金(60467002)
内蒙古自然科学基金(200408020111)
内蒙古师范大学研究生科研创新基金(CXJJS09041)资助项目
