Efficient High-power Single-mode Yb Three-level Cladding-pumped All-solid Photonic Bandgap Fiber Lasers at ~978nm

We report an efficiency of 62.7% with regard to the launched pump from a Yb cladding-pumped fiber laser at ~978nm. ~84W with an M2 of 1.11/1.12 was achieved, a significant improvement from a flexible fiber.© 2019 The Author(s)

1. Background

Yb three-level fiber lasers are very useful for pumping solid-state and fiber lasers due to their wavelength at ~976nm. They can potentially play a significant role in pumping ultrafast solid-state and fiber lasers, which are critically needed for the rapidly emerging micro-machining applications. Diffraction-limited powers of at least a few tens of watts are required for these applications, which can be used to provide diffraction-limited output and much reduced device lengths in order to minimize optical nonlinearities.