Interesting quotes from the article:

"There has not been a significant improvement in the minimum attenuation—a measure of the loss of optical power per kilometer traveled—of optical fibers in around 40 years...

"The new design maintains low losses of around 0.2 dB/km over a 66 THz bandwidth and boasts 45% faster transmission speeds...

"The new fiber is a kind of nested antiresonant nodeless hollow core fiber (DNANF) with a core of air surrounded by a meticulously engineered glass microstructure.

"The team believes that further research can reduce losses even more, possibly down to 0.01 dB/km, and also help to tune the fiber for low-loss operation at different wavelengths. Even the losses achieved, however, open up the potential for longer unamplified spans in undersea and terrestrial cables and high-power laser delivery and sensing applications, among others."

> "The new design maintains low losses of around 0.2 dB/km over a 66 THz bandwidth and boasts 45% faster transmission speeds...

0.2 dB/km is already a pretty common loss ratio, though. It's true that you won't get that over the entire 1310–1550nm range (the ~35 THz range commonly in use), but you generally can't use all of that for long-haul links anyway due to the way repeaters work.

More interestingly, they promise 0.06 dB/km or so in the most relevant bands. If they can keep that up, it would mean less need for amplifiers, which is a Good Thing(TM).