  Weyl points are the simplest topologically-protected degeneracy in a
three-dimensional dispersion relation. The realization of Weyl semimetals in
photonic crystals has allowed these singularities and their consequences to be
explored with electromagnetic waves. However, it is difficult to achieve
nonlinearities in such systems. One promising approach is to use the
strong-coupling of photons and excitons, because the resulting polaritons
interact through their exciton component. Yet topological polaritons have only
been realized in two dimensions. Here, we predict that the dispersion relation
for polaritons in three dimensions, in a bulk semiconductor with an applied
magnetic field, contains Weyl points and Weyl line nodes. We show that
absorption converts these Weyl points to Weyl exceptional rings. We conclude
that bulk semiconductors are a promising system in which to investigate
topological photonics in three dimensions, and the effects of dissipation,
gain, and nonlinearity.
