Chip-scale power booster for light

Abstract

Telecommunications, the internet, and various streaming services are all made possible by ultrabroadband optical fiber networks that span more than a million kilometers and connect the globe. Erbium-doped fiber amplifiers (EDFAs) are one of the most important technologies for global data transfer (1). Mears et al. demonstrated EDFAs in 1987 (2), which not only unlocked the full potential of ultrahigh data-rate optical transfer over a long fiber, but also advanced high-performance laser sources, such as mode-locked erbiumdoped fiber lasers and frequency combs (3). On page 1309 of this issue, Liu et al. (4) report the realization of an ultracompact chip-scale version of the EDFAs, with a performance already comparable to that of commercially available EDFA modules. © 2022 American Association for the Advancement of Science. All rights reserved.