LAN via Laser light.

Data Rate 10Mbps
http://www.nullmodem.com/10BaseT-Crossover.htm

I want to connect two computer with each other with lan card.
As in the above link it seems like that 2 pins of connector carries +, -, data for transmission.
and 2 pins for +, -, receiving data...

Now my view,
In my view lan card transmit differential data on 2 wires(as in above +, -, Td) it is my view but i don't know exact therefore i want to ask u.

I want to know that how Lan card works.
I want to know which pin carries data for transmit
and which for receiving data...


Now the second thing,
I want to convert differential data to single line.. but i don't know that how can i do this. any circuit, any guidance, any link etc.

Now the third,
I want to convert single line data to differential data.. but i don't know that how can i do this. any circuit, any guidance, any link etc.

In fact i have two computer i want to connect them via Laser.

Thanks in advance.

They're called "line drivers".
There's a LOT of problems involved in making a laser communicating at 10MB/sec. That would take one fast receiver!

It's more realistic to aim for computer comm at lower freq- like 9600 baud serial comm. At least to start. Much more realistic.

Speed can't be decrease

I want to transfer large data for several time.
Data is in Gbs....
Therefore speed can't be decrease..

Use wireless network cards instead, a MUCH more sensible and practical solution!.

Main problems

I want to convert differential data to single line.. but i don't know that how can i do this. any circuit, any guidance, any link etc.


I want to convert single line data to differential data.. but i don't know that how can i do this. any circuit, any guidance, any link etc.

as mentioned it's - "line driver" (and "line receiver").
just google for "mouser line driver" etc. and you will see bunch
of $1 chips. They are used in communication like RS422 and RS485
and go quite fast (profibus for example is 12Mbps)

https://www.electro-tech-online.com/custompdfs/2006/09/sn75174.pdf