Systems, devices, and methods for making, replicating, and using curved holographic optical elements (HOEs) are described. A hologram may be optically recorded into a planar layer of holographic film with various measures in place to compensate for changes (e.g., in optical power and/or playback wavelength and/or angular bandwidth) that may result when a curvature is subsequently applied thereto. A hologram may be optically recorded into a curved layer of holographic film with various measures in place to compensate for optical effects of a curved transparent substrate upon which the holographic film is mounted. A curved HOE may be returned to a planar configuration to undergo holographic replication or holographic replication may be performed using a curved master HOE and curved recipient film. The curved HOEs described herein are particularly well-suited for use when integrated with a curved eyeglass lens to form the transparent combiner of a virtual retina display.

The subject matter described herein includes a curved VPH grating with tilted fringes and spectrographs, both retroreflective and transmissive, that use such gratings. A VPH grating according to the subject matter described herein includes a first curved surface for receiving light to be diffracted. The grating includes an interior region having tilted fringes to diffract light that passes through the first surface. The grating further includes a second curved surface bounding the interior region on a side opposite the first surface and for passing light diffracted by the fringes.

A device for continuously replicating a hologram has a coating module to coat a liquid photopolymer onto a first carrier film, a lamination module to apply a second carrier film to the first carrier film coated with the photopolymer to obtain a photopolymer composite including a liquid photopolymer layer between two carrier films, an exposure module having a light source, and a master element with a master hologram to be replicated, and a fixing module to cure the replicated hologram in the photopolymer composite. The master element is axially rotatably mounted, and the exposure module is designed to bring the photopolymer composite in optical contact with the master element, while the light source exposes the master hologram to obtain a replicated hologram in a region of the photopolymer composite.