Why might the U. S. Navy be interested in a blue-green laser for satellite to submarine optical communications

Answer 1

The blue-green is so it will penetrate the oceans. (Water absorbs red and other colours).

Communications by lasers cannot be listened to by enemies or other parties unless they are directly in the beam's path. Combined with encryption the laser communications are very secure.

Also the current VLF (Very Low Frequency) communication systems cannot transfer data very fast so even small messages can take many minutes to transmit. Lasers are capable of very high data rates (just look at CDs and DVDs).

Answer 2

Lasers are directional, and that makes them hard for 3rd parties to detect. When a submarine transmits radio signals, other people in the vicinity might detect them. This is not desirable for a weapon with stealth as its primary benefit.

There won't be any fiber optic cables connecting submarines to satellites for obvious reasons. The atmospher would refract and distort a laser sent through open space. I don't think it would work.

-a submarine qualified ex-Navy officer

Answer 3

Light beams can only be intercepted when in the path from the transmitter, so the communications would be secure and at a much higher data rate than the present ELF system. Blue-green will transmit through seawater the best, so the subs could remain submerged.

Answer 4

wave length. green and blue lasers have shorter wake lengths and could be used to fire 1's and 0's at higher rate... and it could also be that the material of an optical fiber to transmit blue or green could be very different and might be better in other aspects (less noise in the signal, less damping of the signal... etc.)