Ytterbium doped multicore rod-type fiber with 4x4 cores for coherent beam combination.
Image: IAP (University Jena)
Active fibers possess many inherent advantages such as a large surface-to-volume ratio, a high signal gain and an excellent beam quality. Key technologies developed in our group include chirped-pulse amplification (CPA), advanced large-mode-area fiber designs and coherent pulse combination (CPC). The first two concepts reduce the intensity in the fiber core during propagation and, therefore, allow for pulse energy and peak-power scaling. Additionally, coherent pulse combination distributes the power to multiple fibers or multiple temporal replicas. Recent developments focused on compact integration using multicore fibers and multichannel components. As a result of these efforts, our Ytterbium and Thulium based fiber-CPA systems possess some of the world's largest average powers, pulse energies and peak powers. Furthermore, many of these lasers are used for a variety of challenging applications within the framework of our scientific experiments.
Multipass-cell for temporal pulse combination.Image: IAP (University Jena)