I am currently seeking the correct terminology for a beam that expands linearly from a fixed point, resulting in its wavefronts forming spherical surfaces. However, the beam does not expand in all directions; rather, it propagates within a solid cone. As such, the term 'spherical wave' might not precisely describe this phenomenon. I have wondered if the correct term for this might be 'spherical beam' or 'conical beam', but I am not sure if these are standard.
For instance, Gaussian laser beams demonstrate this characteristic behavior in the far field.
