  Pseudospin is an angular momentum degree of freedom introduced in analogy to
the real electron spin in the effective massless Dirac-like equation used to
describe wave evolution at conical intersections such as the Dirac cones of
graphene. Here, we study a photonic implementation of a chiral borophene
allotrope hosting a pseudospin-2 conical intersection in its energy-momentum
spectrum. The presence of this fivefold spectral degeneracy gives rise to
quasiparticles with pseudospin up to $\pm2$. We report on conical diffraction
and pseudospin-orbit interaction of light in photonic chiral borophene, which,
as a result of topological charge conversion, leads to the generation of highly
charged optical phase vortices.
