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Pixel by pixel brightness control was achieved in the 3D 4k holographic replay field results. High accuracy and brightness control is required for maps in military applications and real-time head-up displays.

Current display technologies are limited in projecting floating ultra-high definition images on multiple layers, preventing applications in augmented reality for medical education. Computer-generated holography (CGH) with custom algorithms allows for displaying floating 3D images for augmented reality applications. The limitation of existing 3D display technologies is the lack of clearly-defined anatomical structures and models for medical education The custom algorithm was based on microoptical adaptation of the natural superposition compound human eye with the help of a virtual Gabor superlens and a layering technique. High-resolution Spatial Light Modulators (SLMs) can enable increasing the field of view and display size in CGH. The 3D holographic projection applications require an enlarged field of view for multi-user purposes and can be implemented to deliver presentations from remote settings and as non-invasive practical education in medicine. This technology targets academic medical centres, hospitals and clinics as well as research laboratories. In this work, a layered holographic projection method was developed to display high-resolution (3840×2160 px) 3D floating images in direct-view mode targeting medical education. A computational algorithm was created based on a phase retrieval algorithm and a virtual Gabor superlens to project a hologram on the Liquid Crystal on Silicon (LCoS) display panel of an UHD SLM. A code was programmed for generating multilayer 3D in-eye projections by adding multiple retrieved holograms with an independent Gabor zone plate into each single hologram. The reconstructions were obtained with a HeNe laser (633 nm, 5 mW) and the UHD SLM with reflective phase modulation. 3D holograms were directly observed floating as a ghost image at variable focal distances.

Driver's access to information about navigation and vehicle data through in-car displays and personal devices distract the driver from safe vehicle management. The discrepancy between road safety and infotainment must be addressed to develop safely operated modern vehicles. Head-up displays (HUDs) aim to introduce a seamless uptake of visual information for the driver while securely operating a vehicle. HUDs projected on the windshield provide the driver with visual navigation and vehicle data within the comfort of the driver's personal eye box through a customizable extended display space. Windshield HUDs do not require the driver to shift the gaze away from the road to attain road information. This article presents a review of technological advances and future perspectives in holographic HUDs by analyzing the optoelectronics devices and the user experience of the driver. The review elucidates holographic displays and full augmented reality in 3D with depth perception when projecting the visual information on the road within the driver's gaze. Design factors, functionality, and the integration of personalized machine learning technologies into holographic HUDs are discussed. Application examples of the display technologies regarding road safety and security are presented. An outlook is provided to reflect on display trends and autonomous driving.

A holographic automotive head-up display was developed to project 2D and 3D ultra-high definition (UHD) images using LiDAR data in the driver’s field of view. The LiDAR data was collected with a 3D terrestrial laser scanner and was converted to computer-generated holograms (CGHs). The reconstructions were obtained with a HeNe laser and a UHD spatial light modulator with a panel resolution of 3840×2160 px for replay field projections. By decreasing the focal distance of the CGHs, the zero-order spot was diffused into the holographic replay field image. 3D holograms were observed floating as a ghost image at a variable focal distance with a digital Fresnel lens into the CGH and a concave lens.