RE:DatacentersFirst, this is an optical communication company using light to trasmit data. This normally means higher potential data rates and higher energy needs and greater heat production and data centre cooling costs. The 100gbps data rate they're aiming to achieve is about double what S7 has announced but they should be working on higher data rates. Optical communication is not new so this is not a new concept.
I don't have the information on their heat production, but it's bound to be higher than electronic communication used by S7. Cable size should be similar and data rates will be similar if S7 can double their current speeds. Optical circuitry is normally more costly thatn S7's electronic system.