Colliding circular polarised plane waves

I will introduce a generalisation of the Szekeres class of colliding plane wave solutions obtained by means of an inverse scattering method for the hyperbolic Ernst equation. Instead of the collinear polarisation of the waves within the Szekeres class, the incoming waves feature a monotonically increasing phase angle in their characteristic Weyl tensor component and thus can be regarded as "circular polarised". These waves can occur with two different helicities, and interestingly the interaction properties differ dramatically for collisions of waves with the same or respectively opposite helicities. The class seams also to admit a limit of "circularly polarised impulsive waves".