How to select Fiber Cable (multi-mode or single mode). For example, if i need fiber backbone around 700 meters with 2 GB speed, how i choose, om 2, om 3 or OS 1 & Os 2. Is there any calculator or calculations available for it..?
So you don't specify the connection type (fibre channel? Ethernet? SONET?) but it's safe to say that at 700M you're outside the realm of what should be run with multimode on just about anything.
Since the link needs to be single mode you'd likely have an easier time just using OS1, which has somewhat higher attenuation but is less fragile and thus much easier to run within a building. The lesser attenuation of OS2 isn't going to be a factor until you're into many tens of kilometers.