VRay self-illumination -> Jagged Edges


As soon as self-illumination get stronger than the default values, light-emitting objects, be it Self-illuminating Material / Vray lights / Mesh lights /VRay Light Material,… are getting jagged edges.
Is there a way to have a strong illumination values and get smooth, anti-aliased edges?
Please help!
I am working on a project for a light festival and the scraggy edges are killing me.
Below you see two VRayLights…


Can you show some photo of a light-emitting objects for comparison?


Attached an image using VRay Light Material.