摘要
提出一种相位掩模干涉仪用于对光纤光栅写入不同的Bragg波长。该系统中,光纤光栅由两块可旋转棱镜所形成的紫外干涉条纹写入,其中相位掩模被用作1级衍射光的分束器。当两块顶角由相位掩模的1级衍射角和棱镜折射率确定的棱镜的底部相互平行放置时,该相位掩模给出了Bragg波长的参考值。当Bragg波长的频移为1nm时,棱镜最大的旋转角为1°,最小的旋转角是2.4′。与Talbot干涉仪中平面镜的旋转角23″/nm相比,该相位干涉仪中棱镜的旋转精度降低了2～3个数量级。该可调谐相位掩模干涉仪仅用一块相位掩模和两块旋转棱镜就可实现写入具有不同Bragg波长的光栅,替代了许多具有不同光栅周期的相位掩模。
A phase mask interferometer is developed to write gratings with an arbitrary Bragg wavelength. In this system, the gratings are written by the UV interference fringes derived from two rotatable prisms, and the phase mask is used as a beam splitter. Furthermore, when the undersides of two prisms with the vertex angle defined by the ± 1 diffraction angles of phase mask and the refactive index of the prism are parapllel each other, the phase mask initializes the reference quantity of Bragg wavelength. As the shift of Bragg wavelength is 1 nm, the maximum rotation angle of the prism is 1 o, and the minimum rotation angle is 2. 4＇. By contrasting with the rotation angle 23＂/nm of the mirror in Talbot interferometer, the rotation precision of the prisms is decreased by two or three orders of magnitude in this phase mask interferometer. Instead of many phase masks with different grating periods, the phase mask interferometer can write grating with the written wavelength of 1450 - 1 600 nm via a phase mask and two rotatable prisms.
出处
《中国光学与应用光学》
2009年第5期421-425,共5页
Chinese Optics and Applied Optics Abstracts
基金
云南省科技计划项目:本安光纤光栅热工传感器的研究(2007F181M)
作者简介
李川（1971年-），男，四川成都人，博士，教授，主要从事光纤传感器研制与应用方面的研究。E—mail：boatriver@eyou．com
