Light source module, lighting device and lighting system

A light source module, a light emitting device according to an embodiment of the invention; And disposed over the light-emitting element and the first surface having a groove center through the optical axis, recessed in the light exit direction and, arranged on the first surface opposite to the light is refracted incident through the above groove is discharged to the outside Article comprising an optical element having a second surface, the optical element is characterized in that it is disposed on the second surface with the optical axis at the first surface a plurality of periodic unevenness arranged in a rim direction are connected to the parts.