What are the problems with using light to transmit data

[asathor]

what I am wanting to know is what are the problems with sending data with photons of light? in detail? why have we not got this up and running. I want to know so I can work on some or one of the problems

 

[axmls]

We do!

https://en.wikipedia.org/wiki/Fiber-optic_communication

Electrical engineers and physicists are always striving to get faster and better data transfer over fiber optics. Not only is it up and running, but all of the cables that connect us with Europe, for instance, are fiber optic cables. So yes, we use light wave communication as sort of the backbone of the internet, and we're always working on improving it.

Not only that, but every time you send data over wifi, or cellular data, or radio, etc. you're sending data with photons, since electromagnetic waves (radio waves, microwaves, etc.) are photons! Though I suspect you had visible light in mind, this is the same concept. We use light to communicate all around the world.

 

[asathor]

Thank you. Ya I know most of that I was referring more toThe end of cyber snooping? Quantum Key Distribution (QKD) delivers private data using the smallest possible packets of light. It could be used to transmit encrypted payments between credit card providers and online retailers to prevent people's private information falling into the hands of cyber criminals. I need other perspective on the problems with this tech and ideas on how to fix it. A think tank if u will

 

[nasu]

If you really mean to do some work in the field, you should start with a serious literature research.

 

[leright]

The two main technical problems with fiber optics are material dispersion and modal dispersion (aka waveguide dispersion). Both have the effect of reducing the bandwidth and range of fiber systems.

Material dispersion the fact that there is in reality a small spread of wavelengths transmitted (it is not truly monochromatic) and since speed of light in a medium depends on wavelength the pulse gets spread out. It will eventually get to the point where adjacent pulses overlap and interfere if the bandwidth (or frequency of the signal) is too high given the distance the light is traveling through the fiber.

Modal dispersion is the fact that the fiber has some thickness to it and there are different reflective modes which result in varying speeds of transmission along the fiber, which also has the effect of spreading the pulses. There are extremely thin fibers out there nowadays that allow only a single mode the be transmitted, which eliminates this problem though. Material dispersion is always going to be an issue though.