SYSTEMS, DEVICES, AND METHODS FOR CURVED HOLOGRAPHIC OPTICAL ELEMENTS
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.
1 . A method of producing a curved holographic optical element (“HOE”), the method comprising:
mounting a holographic film on a first surface, the first surface being transparent and having a first curvature; and
optically recording a hologram in the holographic film while the holographic film is mounted on the first surface.
2 . The method of claim 1 , further comprising:
removing the holographic film from the first surface; and at least one of:
mounting the holographic film on a second surface for playback, the second surface having a second curvature substantially equal to the first curvature; or
embedding the holographic film within a curved volume for playback, the curved volume having a second curvature substantially equal to the first curvature.
3 . A method of replicating a curved holographic optical element (“HOE”) that comprises at least one hologram recorded in a holographic film, the method comprising:
providing a first layer of holographic film;
mounting the first layer of holographic film on a first surface, the first surface having a first curvature;
optically recording a hologram in the first layer of holographic film while the first layer of holographic film is mounted on the first surface;
providing a second layer of holographic film;
applying the first curvature to the second layer of holographic film; and
replicating the hologram from the first layer of holographic film in the second layer of holographic film while both the first layer of holographic film and the second layer of holographic film each have the first curvature.