Another one of those mythbuster questions.

RomanNose · 7 Oct 2011 at 19:39

I was just thinking about fibre optic cables, and I just came up with another one of those myth-buster questions.
If you had a domestic fibre to the house connection and it was disconnected at the cabinet, could you look down the fibre cable and see the other side?
I believe you would have to use some sort of lens perhaps on both sides, so what do you think GD?

Brian8bit · 7 Oct 2011 at 19:40

There's a laser shining through it. You'd melt your eye.

RomanNose · 7 Oct 2011 at 19:40

Brian8bit said:
There's a laser shining through it. You'd melt your eye.

...
If it was disconnected at the other side..

Brian8bit · 7 Oct 2011 at 19:42

Then no you couldn't.

RomanNose · 7 Oct 2011 at 19:43

Brian8bit said:
Then no you couldn't.

Why?

touch · 7 Oct 2011 at 19:45

You'd need some sort of lense to be able to look down it but, yes, you would be able to see.
A fibre optic cable is just a tunnel that light travels through which allows you to 'bend' the light to where it needs to go. You could get the same effect with a straight tube the same length and diameter. You wont see very much, especially if its dark.

ps3ud0 · 7 Oct 2011 at 19:45

Isnt it something to do with the light going through it not will have the right properties to internally refract within the fibre allowing you to see to the other side.

Thats why you use laser...

Wow Ive never felt thicker

ps3ud0

Brian8bit · 7 Oct 2011 at 19:47

If it's disconnected from an intense light source like a laser, you'd be limited to how far naturally occurring light can travel down a fibre optic cable?

This makes more sense in my head than it does written down...

ng93 · 7 Oct 2011 at 19:47

IIRC doctors use fibre optics to look up/down people, so yes.

Edit: this may be entirely wrong though.

needforspeed · 7 Oct 2011 at 19:48

Like a Fiberscope in the Splinter Cell game? lol. You probably need to attach something?

lord filbuster · 7 Oct 2011 at 19:50

No, the bit that carries the light is thinner than a hair. There's no way you could see down it.

RomanNose · 7 Oct 2011 at 19:51

So it is possible, the question is. Why is it that a fiberscope can only relay one colour?

ps3ud0 · 7 Oct 2011 at 19:56

chaosdestro0 said:
So it is possible, the question is. Why is it that a fiberscope can only relay one colour?

No your question above isnt possible - you need LASER light to propagate down the length of the fibre.

One of the properties of LASER is a single wavelength of light i.e. a single colour

ps3ud0 :cool:

Slade2 · 7 Oct 2011 at 19:58

Ok Total internal refraction means you would have course see some light if it was on at the other end.

From google search : -

The light in a fiber-optic cable travels through the core (hallway) by constantly bouncing from the cladding (mirror-lined walls), a principle called total internal reflection. Because the cladding does not absorb any light from the core, the light wave can travel great distances.

However, some of the light signal degrades within the fiber, mostly due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light (for example, 850 nm = 60 to 75 percent/km; 1,300 nm = 50 to 60 percent/km; 1,550 nm is greater than 50 percent/km). Some premium optical fibers show much less signal degradation -- less than 10 percent/km at 1,550 nm.

--

So, yes you would be able to see the light from one end at the other end. My gran used to have a fibre optic light from a few years ago which I always thought was really cool when I was a kid.

I know Fiber Optic Splicing is quite an art and there are a number of ways of joining the cables but thats a whole different subject.