Mitigation strategies for mode instabilities in high-power fiber-laser systems

In this contribution, experimental approaches to control mode instabilities (MI) at average output powers higher than 330 W, which corresponds to three times the typical power threshold of the fiber laser system in use, is presented. Hereby, an acousto-optic deflector is used to change rapidly the beam position of the seed signal on the fiber core at the input side. Dynamic excitation is combined with an electronic feedback loop to actively stabilize the beam profile.