Amethyst lenses: light repeater

Sort of like repeaters for redstone, these blocks would release full light level if it is in any level of light. These could be very useful for educational ways of transferring information over long distances, as a long chain of them could make something like an optic fibre. Connecting the chain to a redstone lamp at the beginning and a daylight sensor at the end, you could send redstone signals over long distances. This may seem overpowered, so there should be a very small delay between each lens. 

The rest is up to you: what texture does it have? How do you craft it? How long does  it delay? Please comment any ideas below.