The main goal of this work is to exploit the excellent gain characteristics provided by rare-earth ions when doped into potassium double tungstate RE:KYW) materials in combination with the tight field confinement provided by high-contrast waveguides, which enhances non-linear effects and permits the realization of low-loss sharp bends, to explore the realization of very compact, efficient, tunable on-chip lasers and frequency combs in different wavelength ranges for applications in optical sensing, spectroscopy, metrology and telecommunications.
