Abstract: The present invention relates to an optical system for directing light from an image source to a viewer's eye. The system includes an image source providing an image source light; a collimator for receiving the image source light and converting the received image source light into a collimated light projected along a first optical path; and a planar diffractive relay including opposing planar surfaces longitudinally oriented substantially along a second optical path, the opposing planar surfaces terminating into an input tilted surface and an output tilted surface. The collimated light is projected along the first optical path and redirected by the input tilted surface as propagated light traveling in the second optical path. The propagated light traveling in the second optical path is redirected by the output tilted surface into a third optical path directed toward the viewer's eye.

Abstract: The present invention relates to an optical system for directing light from an image source to a viewer's eye. The system includes an image source providing an image source light; a collimator for receiving the image source light and converting the received image source light into a collimated light projected along a first optical path; and a planar diffractive relay including opposing planar surfaces longitudinally oriented substantially along a second optical path, the opposing planar surfaces terminating into an input tilted surface and an output tilted surface. The collimated light is projected along the first optical path and redirected by the input tilted surface as propagated light traveling in the second optical path. The propagated light traveling in the second optical path is redirected by the output tilted surface into a third optical path directed toward the viewer's eye.

Abstract: A night vision device comprising a facemask housing assembly having a peripheral surface defined by a rear surface contoured to a user's face and an open front surface, the housing assembly operative for encasing a pair of optical assemblies operative for receiving light from a viewed object via a first folded optical path and via a second direct optical path, combining the light from the first and second paths, and directing the combined light to a user's eye for viewing the object; where each optical assembly detachably coupled to the housing assembly.