An ophthalmic endoilluminator is provided. The ophthalmic endoilluminator includes a light source, a first optical assembly, an optical coupling element, and an optical fiber having an optical grating located distally on the optical fiber, the optical fiber optically coupled to the optical coupling element. The first optical assembly receives and substantially collimates the white light. The optical coupling element receives the substantially collimated white light from the first optical assembly and directs the light to an optical fiber. The optical grating couples to the distal end of the optical fiber, the optical grating having a surface relief grating, and an overlayer optically coupled to the surface relief grating. The optical grating is operable to substantially diffract incident light into N diffraction orders, the N diffraction orders having a substantially uniform intensity.
