In this paper, we investigate nearly homogeneous radiation with controllable divergence angle by a metallic subwavelength slit surrounded by periodically corrugated grooves. Based on mode expansion method, the parametric investigations show that the unconventional homogeneous radiation is mainly dominated by the non-linear phase distribution in the slit and grooves. Further, the controllable beam divergence and multiple directional radiations are discussed for the potential application in subwavelength beam manipulation.
