If you get light into a clear material which has a reflective surface( almost any clear material does ;) ) then the light will reflect internally and flow down

If you get light into a clear material which has a reflective surface( almost any clear material does ;) ) then the light will reflect internally and flow down the material, while seeping out the sides. That is how fiber optics works, but it doesn't have to be fiber, almost any clear material would do...