A passively mode-locked Holmium fiber oscillator based on a Nonlinear Amplifying Loop Mirror operating at 2050 nmChristoph Mahnke, Yuxuan Ma, Sarper Salman, Christoph M. Heyl and Ingmar HartlEPJ Web Conf., 243 (2020) 04002DOI: https://doi.org/10.1051/epjconf/202024304002