Abstract

A light source arrangement for substantially enhaning the lighting intensity of the light beams emitted from the light source therefore includes a lens body and an illumination unit. The lens body has an illumination portion defining a light projecting surface and at least a diffraction portion defining a light diffraction surface inclinedly extended at a diffraction angle, wherein a diffraction density of the illumination portion is different from that of the diffraction portion. The illumination unit is covered by the lens body for radially generating light towards the illumination portion. When the light reaches the light diffraction surface of a diffraction portion at an angle larger than the diffraction angle, the light is substantially reflected at the light diffraction surface back towards the light projecting surface, such that the light from the illumination unit is converged to project at the light projecting surface of the lens body.