The goal of the project is an experimental realization of tunable sources at 2 um and beyond. Various approaches were investigated including the use of non-silica based fiber optical parametric oscillator pumped at C- and L- telecommunication bands (1530-1620 nm) and thulium doped fiber lasers.
This project resulted in the in depth experimental characterization of various fluoride glasses based fibers (ZBLAN), in terms of their non linearity and dispersion properties. Only weak nonlinear parametric interactions could be measured. Thulium doped silica fibers were also characterized, revealing a relatively high nonlinearity and significant four-wave mixing. Leveraging such properties, we exploited thulium doped fibers or Kerr-nonlinear switching element in mode-locked fiber lasers, with significantly less length of fiber and thus increased repetition rate. Within this project, we also significantly contributed to the development of thulium doped fiber lasers operating in continuous wave and pulsed regime, with high wavelength tunability, and novel architectures.
Funding source: SNSF