a light guide configured to guide light as guided light;

a high-index light guide layer optically connected to a surface of the light guide and configured to extend a thickness of the light guide, a refractive index of a material of the high-index light guide layer being greater than a refractive index of a material of the light guide;

a diffraction grating adjacent to the high-index light guide layer, the diffraction grating being configured to diffractively scatter out a portion of the guided light as emitted light; and

a reflective island aligned with and having an extent corresponding to an extent of the diffraction grating, the reflective island being configured to reflect light diffractively scattered by the diffraction grating in a direction corresponding to a direction of the emitted light, wherein the diffraction grating and the reflective island, in combination, represent a reflection mode diffraction grating.