光纤布拉格光栅反射谱旁瓣的抑制

摘要

计算分析了光纤布拉格(Bragg)光栅中折射率变化分布,折射率变化直流分量对反射旁瓣(Sidelobes)的影响;采用二次曝光技术,用高斯光束和均匀相位模板刻制出反射旁瓣受到有效抑制的光纤布拉格光栅,使光栅的主反射带具有相当锐利的边裙.%The so-called raised G aussian distributed index change,in which its d.c.component keeps constant,is ac hieved by using the double exposure technique with a uniform phase mask and Gaus sian UV laser beam.The reflected spectral sidelobes of the grating can be suppre ssed to below -30 dB and the related channel bandwidth is as narrow as expected.