Now, researchers in England have created a new type of hollow-core fiber-optic cable that can reduce signal loss and increase propagation speed through the fiber. The researchers have doubled the fiber's glass layers, adding a second ring of nested glass tubes. A simple hollow glass tube, however, would not be sufficient to confine light within the air core. This property is useful in myriad technical applications, such as for data transmission in telecommunications, in medical applications, and in lamps and other lighting systems. However, AI data centers today demand more bandwidth still.