中文摘要：

回顾过去20多年来关于紫外光致光纤折射率变化原因的研究成果，同时，详细介绍了目前有关该问题的最新研究成果。从非氢载和氢载两类光纤的角度出发，分别阐述不同种类的光纤在248nm紫外光源激励下形成光纤光栅的机理，为今后深入研究紫外光致折射率变化机理做铺垫。

英文摘要：

The paper reviews the research results about the cause of UV induced fiber refractive index change in FBG of the past 20 years, at the same time, introduces the latest research about this problem in detail. From the perspective of the hydrogen loaded and non-hydrogen loaded fiber, and elaborates the mechanism of index change in optical fibers induced by 248nm UV laser, in order to further study the main cause of index change excited by UV lasers.