An endoilluminator system includes an endoilluminator probe and an illumination source. The endoilluminator probe includes a nano-scale optical fiber and a probe fiber connector, and the illumination source includes a source fiber connector. The illumination source is configured to produce an illumination spot at the source fiber connector having a diameter smaller than a diameter of a fiber core of the nano-scale optical fiber. The probe fiber connector and the source connector are configured when connected to align the illumination spot off-center relative to the nano-scale optical fiber such that the angular distribution of light emitted by the nano-scale optical fiber is increased relative to aligning the illumination spot at a center of the nano-scale optical fiber.