This idea was posted before. See Fiber Optic Lighting.

The idea of redirecting sunlight is great and I like it. I believe that a 'solar tube' which is a mirrored tube may be better than fiber, since they're common already.

But for the night-lighting, I don't see that this is helpful. You'd always have to produce enough lumens to light your whole house, even when you only need one light. It would probably run most of the time, since people are up in many homes both early and late. Fiber optics are expensive and not so efficient to get the light into and out of, so you'd suffer an efficiency penalty of a few percent that direct lighting doesn't have. High brightness lamps tend to burn and melt fiber-ends that are too close.

Once I worked on an avionics set-up that was trying to light displays this way. We had a great-big hot light and still couldn't get enough fiber-light for a single large display to be daylight visible. The company we used still offers this product, google 'lumitex.'