What material excists that can direct light to a point? (see diagram)

Question

Now i don't mean like a magnifying glass. I need something about an inch thick that will direct light to a point on the other side of it.

like this image: http://joeyjoe.co.uk/light.jpg

it doesnt have to be the middle of the bottom, can be at the sides or somthing. and really doesnt have to be a direct point, can be an inch squared or what ever.

using a lense will mean the whole thing will need to be quite wide.

Answer 1

No matter what you call it, what you are asking for is really a  convex lens.You can use a high refractive index material and make the lens thin. Of course the shape will not be what is shown in the diagram, but a convex-lens shape. If you don't mind losing most of the light, of course you can use a pin-hole.

Answer 2

If you need a rectangular slab as shown in the diagram, you can use a glass slab with a refractive index gradient (large in the middle, lower off to the sides). The idea is the same as a convex lens, but it is achieved by varying the material property, rather than the thickness, across the length of glass.

You can read more about it here: http://en.wikipedia.org/wiki/Gradient_in...

and here: http://opticsnotes.nixsar.com/sciopticsf...

I believe what you want is a Wood lens.

Answer 3

I'd agree with Nobody...a Fresnel lens is probably what you need.

http://www.sciplus.com/

This company offers a wide variety of them.

Answer 4

do you remember the old rear projection screens?  they use lenses that are pretty flat (a few mm, can be made of crappy plastic), since the lens only refracts at the boundaries it only needs the edges to work

look

http://en.wikipedia.org/wiki/Fresnel_len...

how about that?!

Answer 5

YES...... THE CONVEX LENSES do that.