Once again I’m too lazy to look all this in wikipedia - if there once was a goal in this set of questions, I’ve already forgotten it…
When light passes a prism, how much energy is wasted when it’s converted back to white light in another prism. OK - it depends on the material, but what would be the best outcome:confused: How about optical fibre:smack:
I do not think any energy would be lost by the splitting and recombining as such. Some energy will absorbed by the glass of the prisms, but no more than would be lost by passing through a sheet of glass of equivalent thickness. (How much that is will depend on the type of glass, and what that thickness is, amongst other things, so, as you do not tell us anything about that, no actual figures can be given.)
To answer the photoelectric effect questions: yes, light can penetrate to the nucleus. If it’s visible light, the photon will most likely just bounce off of the nucleus and head off in another direction. (It’ll lose a tiny amount of energy due to the recoil of the nucleus, à la Compton scattering, but not much.) If you use shorter-wavelength photons, though — X-rays or gamma rays — you can momentarily put the nucleus into an excited state, just like you can use visible light to put orbiting electrons into an excited state. It’s even possible in principle for a sufficiently energetic photon (almost certainly a gamma ray) to cause a nucleon to be ejected from the nucleus, in a process analogous to photoionization.
MikeS, I never knew that photons could cause a type of radioactive decay by penetrating a nucleus! What is this process called? Is there a wikipedia article on it? How are these sorts of things written out in nuclear reaction --> notation?
Something like He + γ -> H + p, for a lame example (ignoring the charges because I’m lazy)?
For fiber, if transmission speed is any indication, fiber isn’t very efficient since light only travels at roughly 70% of c whereas in a newly developed hollow core fiber they have managed speeds of 99.7% c.
But I don’t think there’s much signal loss. I think you can go more than 100km before you need to boost the signal but I’m not sure.
LIght does not travel straight down an optical fiber. It bounces back and forth along the inner core. This total internal reflectivity is what enables optical fiber to work. Even the most efficient single-mode fiber with light aimed straight down the center will develop a mode (describes the bouncing path light will take in it’s trip) as soon as it flexes. So, you give the light beam a slightly off-center angle and tinker with it’s reflectivity so any beam off that angle is reflected back at an angle slightly closer to the desired angle. (All but the cheapest of optical fibers will have this sort of continuously varying angle of reflectivity)
I was curious about that. I knew that fiber worked that way but nothing I’ve read about the hollow core fiber explained if it still had that same property. I assume it had to and that even with bouncing around inside the core, it didn’t really matter.
