  We experimentally demonstrate resonance of first-order vector vortex beams
(VVB) with a triangular optical cavity. We also show that, due to their
symmetry properties, the so-called radial and azimuthal VVBs do not resonate at
the same cavity length, which could be explored to use the triangular resonator
as a mode sorter. In addition, an intracavity Pancharatnam phase shifter (PPS)
is implemented in order to compensate for any birefringent phase that the
cavity mirrors may introduce.
