  Weyl points are robust point degeneracies in the band structure of a periodic
material, which act as monopoles of Berry curvature. They have been at the
forefront of research in three-dimensional topological materials (whether
photonic, electronic or otherwise) as they are associated with novel behavior
both in the bulk and on the surface. Here, we present the experimental
observation of a charge-2 photonic Weyl point in a low-index-contrast photonic
crystal fabricated by two-photon polymerization. The reflection spectrum
obtained via Fourier Transform Infrared (FTIR) spectroscopy closely matches
simulations and shows two bands with quadratic dispersion around a point
degeneracy. This work provides a launching point towards all-dielectric,
low-contrast three-dimensional photonic topological devices.

Optics;Mesoscale and Nanoscale Physics