Design of waveguide holographic configuration for display

In a holographic waveguide display system, the inconformity of grating parameters of input grating, turning grating and output leads to a lot of difficulties in system design and gratings fabrication process. The main condition that the turning grating should be in 60° conical mounting, on which all the gratings in a waveguide holographic display configuration have uniform grating periods, was presented by comparing the grating equations in normal mounting and conical mounting. Under this condition, a novel efficient display was proposed by using a waveguide holographic configuration with three holographic gratings of the same grating periods recorded on a single substrate and a reflector placed on the side face of the substrate. The validity of this configuration was proved by the simulation carried out by the optical design software CODE V. The coupling efficiency loss and invalid area can be dramatically reduced by the reflector on the side face, compared with the traditional configuration. Moreover, the complexity of system design and holographic manufacture can be decreased because all gratings used in the proposed design have uniform grating periods and two of them have uniform orientation. The configuration can be applied to virtual reality display or wearable display. ©, 2015, Chinese Optical Society. All right reserved.