  The traditional head-up display (HUD) system has the disadvantages of a small
area and a single display plane, here we propose and design an augmented
reality (AR) HUD system with multi-plane, large area, high diffraction
efficiency and a single picture generation unit (PGU) based on holographic
optical elements (HOEs). Since volume HOEs have excellent angle selectivity and
wavelength selectivity, HOEs of different wavelengths can be designed to
display images in different planes. Experimental and simulated results verify
the feasibility of this method. Experimental results show that the diffraction
efficiencies of the red, green and blue HOEs are 75.2%, 73.1% and 67.5%. And
the size of HOEs is 20cm*15cm. Moreover, the three HOEs of red, green and blue
display images at different depths of 150cm, 500cm and 1000cm, respectively. In
addition, the field of view (FOV) and eye-box (EB) of the system are
12{\deg}*10{\deg} and 9.5cm*11.2cm. Furthermore, the light transmittance of the
system has reached 60%. It is believed that this technique can be applied to
the augmented reality navigation display of vehicles and aviation.
