Research On Optical Display System Based On Planar Waveguide

The head-mounted display is a visual optical system that projects the virtual information displayed on the micro-display to the human eye for user observation.With the rapid development of information technology in recent years,the head-mounted display is increasingly used in daily life and military applications.It plays an important role in various social application fields,so the research on helmet display technology is of great significance.However,the current head-mounted displays generally have the problems of large size and heavy weight,which has become an important factor restricting the development of head-mounted displays.In order to meet the development requirements of the small size,light weight and large exit pupil of the helmet display,in this paper,a micro-mirror array structure and a surface micro-structured waveguide display optical system are designed and simulated based on planar waveguide.The thickness of the system waveguide is only3 mm,and the system can realize one-dimensional expansion of the exit pupil.Aiming at the problem of exit pupil expansion,this paper further proposes and designs a grating planar waveguide display optical system.The grating is used as an optical coupling element to solve the contradiction between the thickness of the microstructure planar waveguide and the exit pupil expansion.The grating planar waveguide system can realize the two-dimensional expansion of the exit pupil of the system by using three gratings attached to the surface of the planar waveguide,and the thickness of the waveguide is only 3mm,which reduces the weight and volume of the display system.This paper simulates a single-wavelength grating planar waveguide display optical system of red,green,and blue light,and realizes two-dimensional exit pupil expansion.The exit pupil size of the system is twice that of the entrance pupil,and the imaging effect is clear.Finally,in order to achieve multi-color light emission,the optical system of the grating waveguide display system was studied using a dual-color light source,and the feasibility of the multi-color light emission of the grating waveguide was verified.The waveguide display system based on the planar waveguide design in this paper is helpful for the development of helmetdisplay systems towards light weight,miniaturization and large exit pupil.