High power fiber lasers: current status and future perspectives [Invited]

TLDR

The dramatic increase in output power of rare‑earth‑doped fiber lasers over the past decade, enabled by cladding‑pumped architectures, has produced devices with exceptional power, beam quality, efficiency, and wavelength flexibility, largely due to the fiber’s geometry that mitigates heat and converts low‑brightness diode pump light into high‑brightness output. This review examines the current state of continuous‑wave and pulsed ytterbium‑doped fiber lasers, the dominant gain medium, and the challenges of extending the technology to other rare‑earth dopants and wavelengths. The authors analyze key performance‑limiting factors—thermal management, optical nonlinearity, and damage—across different operating regimes while surveying existing designs and architectures. They anticipate future advances in pump laser technology, fiber design, architectural approaches, and functionality that will enhance performance and broaden industrial and scientific adoption.

Abstract

The rise in output power from rare-earth-doped fiber sources over the past decade, via the use of cladding-pumped fiber architectures, has been dramatic, leading to a range of fiber-based devices with outstanding performance in terms of output power, beam quality, overall efficiency, and flexibility with regard to operating wavelength and radiation format. This success in the high-power arena is largely due to the fiber's geometry, which provides considerable resilience to the effects of heat generation in the core, and facilitates efficient conversion from relatively low-brightness diode pump radiation to high-brightness laser output. In this paper we review the current state of the art in terms of continuous-wave and pulsed performance of ytterbium-doped fiber lasers, the current fiber gain medium of choice, and by far the most developed in terms of high-power performance. We then review the current status and challenges of extending the technology to other rare-earth dopants and associated wavelengths of operation. Throughout we identify the key factors currently limiting fiber laser performance in different operating regimes—in particular thermal management, optical nonlinearity, and damage. Finally, we speculate as to the likely developments in pump laser technology, fiber design and fabrication, architectural approaches, and functionality that lie ahead in the coming decade and the implications they have on fiber laser performance and industrial/scientific adoption.