ZEISS holographic optics set new benchmark for vehicle displays

Modern vehicle cockpits require displays that go beyond improvements in brightness and resolution. They need to be fundamentally safer, more ergonomic, and spatially efficient. The relentless challenge facing automotive manufacturing lies in integrating expansive display features - such as a large field-of-view (FOV) and high luminance - without compromising precious packaging space (ie components placement) or introducing burdensome complexity into the production line.

While existing technologies like Augmented Reality Head-Up Displays (AR-HUDs) and Panoramic HUDs (P-HUDs) have attempted to bridge this gap, they often impose rigid installation constraints and significant trade-offs between features and packaging. ZEISS Microoptics has engineered a sophisticated solution rooted in Holographic Optical Elements (HOEs), designed to bypass these limitations whilst providing a definitive path to industrial-scale manufacturing. These HOEs represent an elegant optical feat.

As Christoph Erler, Head of Advanced Development, CTO at ZEISS Microoptics states in his co-authored paper, Shaping the Future with Holographic Transparent Displays (2025): “Holographic optical elements (HOEs) are used nowadays as an innovative approach to realise different optical functions in transparent media and to make glass smart, which was not possible or limited using conventional optical elements such as lenses or mirrors.”

By integrating a HOE layer into a transparent substrate, such as a vehicle’s windscreen or side window, ZEISS allows the glass itself to perform complex optical functions previously relegated to bulky mirror or lens assemblies.

The decoupling advantage: Performance liberated from packaging

The operational feasibility of any new component in automotive design rests heavily on its physical footprint and performance requirements. Here, the HOE technology delivers a crucial advantage. The HOE functions by redirecting light from an LED- or laser-based projector to the driver’s viewing area (the eyebox) via diffraction.

The HOE also offers a valuable privacy function, achieved because the light redirection is defined. The display is visible only within the precisely defined eyebox; once the viewer's head moves out of this zone, “the whole image disappears completely and simultaneously,” offering a distinct benefit for compartmentalised information delivery. Furthermore, since the HOE responds only to the specific light angle and wavelength of the projector, it remains highly transparent, achieving ambient light transmittance levels above 92%.

Industrialising the process: Seamless integration and volume readiness

For manufacturing and production leaders, the primary concern is the seamless transition from R&D innovation to high-volume series production. Consolidating cross-domain expertise spanning concept design, Holographic Optical Element (HOE) mastering and replication, automotive windshield lamination, and PGU/HMI integration, ZEISS has been driving the establishment of an ecosystem and teaming up leading suppliers across the supply chain to deliver a defined and ready-to-deploy supply chain to OEMs with best-in-class speed, quality and cost efficiency.

Durability is ensured through robust engineering. The proprietary photopolymers, polymers, and glass are engineered with advanced formulations to cure rapidly - in seconds - and withstand the tough “serial production steps, thermal cycles, and automotive handling”. The resulting architecture is subjected to rigorous validation via “accelerated life, environmental, and vibration testing per automotive norms,” substantially mitigating downstream warranty and complaint risk.

Future-Proof: The analogue advantage

When it comes to generating a hologram, there are two primary approaches: analogue and digital methods. For windshield displays, where the highest quality and performance are paramount, ZEISS opts for the more challenging analogue recording method.

In digital holography, pixels are recorded side by side. However, even at the highest quality, gaps between pixels can cause light loss and limit image fidelity. This means the hologram itself can become the limiting factor for image quality.

In contrast, the analog method employs laser technology to record a continuous layer of microstructure into the photopolymer. This ensures that the hologram does not become a bottleneck for display performance. Consequently, analogue holography offers enough potential to address 4K resolution and even beyond.

Crucially, ZEISS has made a strategic choice to favour analogue production methods over digital ones. While digital methods segment the HOE into 'hogels' (pixels), which limits the display’s ultimate resolution, ZEISS employs an analogue method where the entire HOE is composed of “continuous, non-pixelated microstructures”.

Such a technological choice ensures that the “resolution of the transparent display depends only on the resolution of the projector,” as stated by the authors in Shaping the Future, effectively future-proofing the component. The analogue process utilises precision replication technology, where a master hologram is recorded under exacting cleanroom conditions, and subsequent copies are faithfully reproduced in typical manufacturing environments.

Finally, even the integration of the projector unit into the finished vehicle is highly automated. ZEISS collaborates with automation specialists to supply “vision-guided, robot-based projector alignment solutions,” ensuring “fast, repeatable opto-mechanical integration with minimal operator effort”. This holistic focus on automation and integration capability fulfils the stringent requirements necessary for maximal flexibility, low PPM defects, and rapid volume ramp-up.

In summary, ZEISS’s holographic transparent display technology offers an elegant solution that resolves critical conflicts in vehicle production and design. Critically, the manufacturing investment in robust analogue holography replication and streamlined supply chain solution positions the HOE as an industrially mature component ready for global serial production.

As the paper concludes: “The analogue production method is chosen to fully release the potential of the HOE for the display function. With the full manufacturing value chain of ZEISS to realise series production, high quality HOEs could be brought to every car and every home to make the glass smart.”