Hi all, So I'm working on a project, and I'm having some design issues. I need a method of taking a white light source, and directing all of the photons that it emits in a single direction. I have a model in mind, involving an arrangement of layered components. Bottom layer: Light source. Rectangular panel as simple as a thin box with opaque or reflective sides and bottom, a transparent top, and some LEDs inside. This is only an example. Layer one just needs to emit white light. Top layer: Placed on top of the bottom layer. Photons emitted from the bottom layer that pass through this layer travel in a perpendicular direction (or close to) when they leave through the other side. So obviously my confusion is with the top layer. The only idea that has come to me deals with using layers of materials with specific indices of refraction such that photons creating too large of an incident angle will undergo total internal reflection. The problem with this is that it requires some material with a sufficently large index of refraction which I don't even think exists. Any suggestions? Places to start researching? For any information you can provide, thank you for your help!