China makes advances in laser-propelled submarines (opens in new tab)

That’s scmp for you.

In comparison to conventional nuclear sub this method would be much quieter. But also much faster over long distances. You have two issues with subs, stealth and positioning. If you know, or have high confidence, that a combatant sub force is in X pos, and have Intel on its AVG speed then you can plan accordingly. Tech like that described above means a sub force can be more quickly repositioned, or deployed. You have Intel that X vessel was docked two days ago? Well it could be in the south pacific today.

One thing to keep in mind, there is a reason this is published publically. PLA want this out there for a reason, either to sow worry and concern or to mislead.

Yeah, if I'm understanding what's going on here, it's going to be noisy as hell.

Cavitation noise isn't the only factor making a submarine detectable, but it's definitely high on the list. It's been used to detect submarines since WWII or thereabouts.