What does "index unit" imply when object defined dielectric is used ?
I am a new Lumerical User. From Lumerical University's tutorial on FTDT, I came to know that we can use an object which has a user-specified refractive index. But below the "index" text box, there's also an option to select the index units. I am confused at this, since I know that refractive index does not have a unit.
Would you kindly explain what the "index units" imply? Thanks.