Techniques disclosed herein relate generally to eye-tracking in near-eye display systems. One example of an eye illuminator for eye-tracking includes a substrate transparent to visible light, an array of light sources immersed in the substrate and configured to emit infrared light, and a holographic optical element conformally coupled to a surface of the substrate and encapsulated by an encapsulation layer. The holographic optical element is configured to transmit the visible light and diffract the infrared light emitted by the array of light sources to the eye of a user for eye-tracking.