We propose a holographic augmented reality (AR) display by using a cylindrical holographic optical element(HOE). The cylindrical HOE is used as a wavelength-selective reflective screen. A three-dimensional (3D) objectis not reconstructed on the cylindrical HOE directly, but behind it as a virtual image. Thus, it becomes possibleto superimpose the 3D reconstructed image with a real-existent 3D object without physical contact: augmentedreality can be achieved. Moreover, in our method, the shape of the HOE is not planar but cylindrical. Thanks toits shape, the viewing zone of our method becomes much wider than that of planar hologram, where the viewingzone is fundamentally limited to only the forward region of the planar hologram. In our method, informationof the 3D object to be reconstructed is coded into a conventional planar hologram such as a spatial lightmodulator (SLM). Then, the wavefront modulated by the planar hologram enters the cylindrical HOE. Becausethe cylindrical HOE reflects the incident wavefront with a very wide diverging angle, viewers can observe the 3Dobject from a very wide horizontal range. For this purpose, our method utilizes the reflection on the cylindricalsurface. Thus, holograms for modulating the wavefronts have to be designed considering the reflection on thecylindrical HOE properly. In our method, wavefront propagation via the cylindrical HOE is calculated based onthe geometric optics. To verify our method, we performed optical experiments, and our holographic AR displaywas successfully demonstrated.
展开▼
