High-power mode-locked 2 <i>µ</i> m multimode fiber laser

Abstract

Abstract We report mode-locking operation of a multimode thulium fiber laser at 2 µ m with a semiconductor saturable absorber as the modulator. Through synchronization of different transverse modes, multimode mode-locking has been achieved with an average power &gt;10 W. Based on a large mode area, the pulse energy is over 500 nJ, and the pulse peak power is over 10 kW. Such multimode-locking of fiber lasers shows substantial enhancement in both pulse energy and average power (peak power) compared to their traditional single-mode counterparts, providing a new kind of high power ultrafast laser source that can be used in various areas.