Angled fiber-coupled MgF[formula omitted] microcavities for nonlinear optics in 1.5 and [formula omitted] bands.

A versatile angled fiber coupling platform for magnesium fluoride whispering gallery mode resonators is used to investigate nonlinear frequency conversion across 1.5 and 2 μ m bands. We characterize MgF 2 microcavities of varying sizes (4.3 mm, 1.9 mm, and 0.73 mm in diameter), achieving quality factors up to 2 × 1 0 9 at 1. 55 μ m and 5 × 1 0 8 at 1. 94 μ m. In the telecom regime, we observe rich nonlinear phenomena including Kerr comb generation, Brillouin lasing, and Raman lasing. Extending to the 2 μ m band, we demonstrate four-wave mixing in a sub-millimeter cavity, highlighting the platform's potential for the 2 μ m band mid-infrared nonlinear optics. [Display omitted] • Angled fiber coupling enables nonlinear optics in MgF 2 cavities at 1. 5 μ m and 2 μ m. • Kerr comb, Brillouin and Raman lasing observed in 730 μ m MgF 2 cavity at 1. 5 μ m. • Report of four-wave mixing in 730 μ m MgF 2 microcavity at 2 μ m wavelength. [ABSTRACT FROM AUTHOR]