I have a homework assignment due tomorrow in laser physics, with a question concerning a lens waveguide. The question seems pretty simple, but I don't know what a lens waveguide is. I have a general idea, that it's alternating convex and concave lenses, but I think there's probably more than that to it, specifically concerning the distances between the lenses and their focal lengths. And all my googling turned up nothing.

So can anyone provide a brief overview of how it works, or provide a link one? It would Please...


Thanks,

Niko