Using arduino for sending information through lasers...

Projects General Guidance
1

Hi! I have got acess to some pretty good lasers with a range of 8-25km ( 5-15 american miles I guess ).
I am very new to arduino but I would like to make som research on digital transfer/information transfer through lasers. And the arduino seems very good for this!

I just first need to know if it is even possible to do what I am about to tell you next;

  1. Connect a Laser that can be controlled through on/off from an output on the arduino bord.
  2. Use a Photoelectric sensor and aim the laser on it.
  3. Use another arduino board connected to the sensor and thus recieve a form of input signal.

Then; how should I decode/encode the signal? Lets say that I will use morse code in the beginning. Is it possible for the arduino board to measure signals in the time domain?
Since every form of digital transfer uses 0/1 and time to separate between blocks of information...
Therefore my arduino board somehow must know how long the signal should be (power on/off) and then the other board should measure how long theese actions take and decode it the same was as it was encoded.

Any ideas? HELP! :)?

2

DWisenhoff:
I just first need to know if it is even possible to do what I am about to tell you next;

  1. Connect a Laser that can be controlled through on/off from an output on the arduino bord.
  2. Use a Photoelectric sensor and aim the laser on it.
  3. Use another arduino board connected to the sensor and thus recieve a form of input signal.

Yes, you can, although the achievable throughput will be quite low compared to commercial laser links. In the best oc cases, it'll just serve as an education project to learn about data transmission. If you intend to do anything useful like connecting a remote location to the internet, better forget about it.

DWisenhoff:
Then; how should I decode/encode the signal? Lets say that I will use morse code in the beginning. Is it possible for the arduino board to measure signals in the time domain?

This wheel has already been invented many times over and there's tons of literature on the subject, some probably dating back to 1950 and earlier. Do some research on the subject. Just a hint, Morse code isn't a good encoding method for a project like this, it has been invented for humans, not machines.

Korman

3

Are you pointing the laser through air or at the end of a fiber cable? Through air with a few km distance and receive on a photo sensor is not possible, unless your sensor is super big in size. Say it's a cm across in size, then the angle it subtends is only 0.01/1000 for 1Km distance, which is too small to adjust and compensate for air diffraction. If you use fiber, it's possible.
I don't know the current technique for fiber comm, turning the diode laser on and off or using a modulator in front of an always on laser.