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physea
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I suppose there's tons of information about optic fibres, but what are they really, their functions, their limitations, pros and cons?
physea said:I suppose there's tons of information about optic fibres, but what are they really, their functions, their limitations, pros and cons?
I guess you could think of it that way. The more technical description is that fiber optic cables are a type of waveguide (https://en.wikipedia.org/wiki/Waveguide) for visible light.physea said:So basically optic fibers are hollow cables with mirror-like inner surfaces that reflect light so that light is transmitted?
Yes, but they are low for good cables. I think I've seen cables where the loss is around 1dB/km.physea said:Are there losses?
Of course. Telecommunication companies use these for internet traffic.physea said:Are they used for information transfer?
NFuller said:I guess you could think of it that way. The more technical description is that fiber optic cables are a type of waveguide (https://en.wikipedia.org/wiki/Waveguide) for visible light.
Yes, but they are low for good cables. I think I've seen cables where the loss is around 1dB/km.
Of course. Telecommunication companies use these for internet traffic.
The wiki article has a long section on applications.physea said:Thanks
Other applications?
Communications is just a small application. This is the largest application of fiber optic cables to date, I believe...physea said:Thanks
Other applications?
NFuller said:Yes, but they are low for good cables. I think I've seen cables where the loss is around 1dB/km.
I'm not sure what you mean by saving a percent loss. Do you mean how much light intensity will be lost over a 2500km cable?physea said:Interesting, from that value, can we save the % loss for 2500km? or per km?
For the ones used in actual applications, not quite so. It's true that a hollow cable having reflective inner surface can also transmit light from one end to the other but such scheme proves to suffer from high amount of loss per unit distance (I either read it somewhere or heard it from someone else, too bad it was long time ago I can't remember the source). In reality, generally speaking optical fibers take the form of a coaxial dielectric and flexible tube tube. It is coax because it consists of at least two 'layers'. The innermost tube is called core and the outer one is called cladding. One of the condition for it to be able to guide light is to have the core having higher refractive index than the cladding. In this way, rays hitting the core-cladding interface will undergo total internal reflection provided the incoming angle is bigger than the critical angle between the two media. As the others have mentioned, there is a wealth of information on optical fiber and a forum thread is by no means sufficient to even cover the basic, you will need an introductory textbook on this topic at the very least. As subfields of optics, optical fibers and lasers pose the same level of breadth and development.physea said:So basically optic fibers are hollow cables with mirror-like inner surfaces that reflect light so that light is transmitted?
NFuller said:I'm not sure what you mean by saving a percent loss. Do you mean how much light intensity will be lost over a 2500km cable?
Over 2500km, using the example given, 2.5dB of the signal is lost. The fraction ##f## of power transmitted is thenphysea said:Yeah sorry typo. I mean how much % will be lost.
NFuller said:Over 2500km, using the example given, 2.5dB of the signal is lost. The fraction ##f## of power transmitted is then
$$f=10^{-2.5/10}=0.56$$
So the fraction of power lost is ##44\%##.
I don't know, you will probably have to do some googling to find the answer. Since this question is not directly related to the original question though, it is probably more appropriate in a separate thread.physea said:Do we know how much light energy is released per gram of petrol or natural gas burned?
berkeman said:Communications is just a small application. This is the largest application of fiber optic cables to date, I believe...
Optic fibres, also known as optical fibres, are thin strands of glass or plastic that are used to transmit information in the form of light pulses. They are commonly used in telecommunication networks to transmit data at extremely high speeds over long distances.
Optic fibres work by using the principle of total internal reflection to guide light along their length. When a light pulse enters one end of an optic fibre, it bounces off the walls of the fibre and travels down its length, emerging at the other end. This allows for the transmission of data at incredible speeds and with minimal loss of signal.
Optic fibres offer several advantages over traditional copper cables. They have a much higher bandwidth, meaning they can transmit more data at once. They are also much thinner and lighter, making them easier to install and transport. Additionally, optic fibres are less susceptible to interference from electromagnetic signals, resulting in clearer and more reliable data transmission.
There are two main types of optic fibres: single-mode and multi-mode. Single-mode fibres have a smaller core, allowing for the transmission of a single mode of light, resulting in higher speeds over longer distances. Multi-mode fibres have a larger core, allowing for the transmission of multiple modes of light, making them more suitable for shorter distances and lower bandwidth applications.
Optic fibres are primarily used in telecommunication networks, such as telephone, internet, and cable television systems. They are also used in medical imaging equipment, such as endoscopes, and in industrial applications for sensing and monitoring. Optic fibres are also becoming increasingly popular in home networks, as they offer faster and more reliable data transmission compared to traditional copper cables.