A simple profile such as a step index matched cladding profile [Fig. 8(a)] or a step index depressed cladding profile [Fig. 8(b)] is sufficient for standard single-mode fiber designs.
如果是标准的单模光纤设计,一个简单的分布图,比如突变型匹配包层光纤[图8-a]或者（越阶）突变型凹陷包层光纤[图8-b],就已经足够.
the step index profile 阶越/突变折射率分布
While it is possible to use a simple step index profile to shift the zero dispersion
wavelength to 1550 nm,…
同时,也可以用一个简单的突变型多模光纤剖面将其零色散波长转换为1550纳米,……