This conference presentation was prepared for SPIE AR | VR | MR, 2024.

To make augmented reality (AR) eyewears widely available, it is necessary to provide a cost-effective and high-quality AR waveguide combiner solution. The polarization volume hologram (PVH) gratings made of liquid crystal (LC) polymer is a promising candidate with unique polarization properties. In this presentation, we review the physical properties of PVH and provide a thorough discussion about how the performance of the waveguide combiner is influenced by the characteristics of PVH and fabrication capabilities. Our study provides guidance to the development of PVH waveguide technology and promotes scale-up solutions.

AR/VR headsets operating in visible wavelengths require extremely compact and lightweight optics to allow for all day wearable comfort and functionality. This means that visible metalenses would be ideal for this application. Visible metalenses have not been available for volume production until now.

With proven visible metalens production the adaptation into applications such as AR/VR are the next step. At Moxtek, we have an established baseline visible meta-optic process line that provides greater than 90% total efficiency on a lot to lot average.

Moxtek is uniquely positioned to support application development with design validation and production ready nanoimprint masters all processed on high volume tool sets.

Our study introduces a novel approach that combines Kogelnik coupled wave theory with BSDF to accurately characterize the diffraction phenomena exhibited by VHOE. By integrating this theoretical framework with ray tracing simulations, we enable the optimization of the system through a synergistic combination of simulated wave propagation and geometric optics. As a result, we have successfully identified and implemented viable solutions, leading to the development of an enhanced AR near-eye system that boasts improved efficiency, compactness, and superior image quality.

Liquid crystal photonic technology has been widely explored in VR systems giving its unique response for polarization. In this paper, we proposed a new time-multiplexed structure for foveated VR display using liquid crystal components. Unlike most other foveated display method, in which several displays are needed, a single display panel was used in the proposed architecture and the viewing optical system can be tuned between high optical power path to provide the wide FOV and low optical power path to achieve the high resolution through a switchable half wave plate (sHWP).

The Vergence-Accommodation Conflict (VAC) presents a well-documented and significant challenge in XR, causing visual discomfort and fatigue. It has been shown that dynamically changing the focus distance of the display enables eye’s vergence and accommodation to agree and has significant user benefits. Bringing focus adjustment to product has numerous challenges including power consumption, space constraints and added mass.

We will present how Shape Memory Alloy (SMA) can be utilised to enable dynamic focal adjustment and how CML’s SMA actuators are particularly well-suited to achieve this with low power and low added mass in a manner suited for high-volume manufacture.

As the basis of virtual content creation, cameras are integral to augmented reality (AR) applications. However, the opaque nature of the camera's appearance can prevent it from being integrated into a transparent AR display. Here we introduced an integrated, compact, and flexible see-through camera, which enables crucial functionalities like eye gaze tracking and eye-position perspective photography, enhancing the immersive experience and interaction possibilities.

In this paper, we present thin-film photodetector (TFPD) image sensors for the short-wave infrared (SWIR) range. Monolithic integration of quantum dot (QD) absorbers enables quantum efficiency of 70% at 1400 nm and pixel pitch below 2 μm. We present image sensors on custom CMOS readout fabricated using 130 nm node. We review latest advancements on the photodiode stack and the pixel engine, including the thin-film pinned photodiode architecture. Furthermore, we study the manufacturing flows to realize full wafer capability for volume processing. QD image sensors are paving the way to add augmented vision into future XR systems with extra functionalities.

Eye-tracking offers vast potential for enhancing the XR experience. Despite the maturity of the technology, challenges persist in achieving the desired level of accuracy, robustness, and population coverage. The challenges arise from the variability of external features of the eye and corneal reflections as well as the many intermediates between them and the fovea. Retinal eye-tracking is a fundamentally different approach, not bound by these constraints. We developed a compact, power-efficient retinal eye-tracking system designed for XR HMDs, circumventing classic limitations and unlocking new possibilities for immersive experiences.

Porotech has developed a single pixel that can create a full range of colours simply by changing how the pixel is driven, called DynamicPixelTuning® (DPT®). This technology can be seamlessly incorporated into an already established market. Porotech has developed several products including full-colour projectors, microdisplay panels, AR glasses, and epitaxy wafers. The company’s panels offer higher resolutions as they are sub-pixel-free, and a longer lifespan due to the use of inorganic materials. Porotech’s projectors and AR glasses can approach currently available optic systems and waveguides, their tuneable wavelength signifies high adaptability to the current market, and the full colour projector is not limited by the type of waveguide used. Compared to the traditional three monochrome panels needed, which impede smooth mass manufacturing, only a single panel is required, meaning manufacturing ease and smaller projectors.

We fabricate all-inorganic, high refractive index optics, including metalenses, waveguides, and diffractive optical elements via nanoimprint lithography with TiO2 nanoparticle dispersion inks and report full-wafer, high-throughput fabrication of waveguides and visible wavelength metalenses lenses with absolute efficiencies greater than 75% (>90% of design efficiency). We employ atomic layer deposition (ALD) as a post-imprint treatment that enables tuning of the refractive index from 1.9 to 2.25 using less than 20 cycles, which improves lens efficiency. Tuning RI of the imprinted optics to match that of the substrates removes concerns about residual layer thickness, resolving a critical issue for some applications. Additional cycles of ALD enable precise tuning of feature dimensions and feature spacings. Finally, we demonstrate the excellent optical and material stabilities of the all-inorganic imprinted optics.

Blazed gratings are widely used for surface relief grating (SRG) waveguides for augmented reality displays. To increase the efficiency and design freedom of blazed gratings the control of the anti-blaze angle has gained attention lately. We will demonstrate mastering processes to realize blazed gratings with positive, vertical and negative anti-blaze angles on masters for the replication of SRG waveguides.

To enable all-day outdoor-compatible smart glasses that wow consumers, waveguide displays cannot be limited by traditional performance trade-offs within the low-index waveguide design space. Waveguides displays must simultaneously achieve great cosmetics, no distracting rainbow artifacts, high efficiencies of >1000 nits/lm and excellent image quality. The Photonics Platforms Business from Applied Materials will present advances in design and materials co-optimization that enable a step-function improvement in display performance, leveraging the already proven and scalable 300mm wafer fabrication equipment platform.

The oldest and most proven technique for fabricating diffraction gratings is mechanical ruling, which has been used for mass market manufacturing since the early 1960’s. In this talk I will give the latest update on Inprentus’ use of contact‐mode lithography for fabricating aperiodic grating‐coupled waveguides for AR. I will show data demonstrating 20‐picometer pitch uniformity, low stray light levels, aperiodic modulation results, and successful replication in a high‐index (n=1.9) resin using commercially available nanoimprint lithography.

Optical system metrology is important for best product quality of XR headsets and their components. The test technology used to qualify these components and sub-modules originates from two different fields: display metrology and optical system test: Display-test-derived systems use widefield optics and test low-frequency "macro"-scale parameters like ISO contrast and color and brightness homogeneity. Because of design choices, these systems cannot test "micro"-scale higher-frequency features like contrast of projected text or chromatic aberrations. The typically non-diffraction limited optical designs do not allow reporting correct values for e.g. MTF because of physics limitations. Higher spatial frequencies corresponding to finer details ("micro"-scale) are the domain of optics testing-derived technology, however the design choices typically used here make testing at the "macro"-level difficult.

In this paper, we demonstrate that neither one of the two technologies is sufficient to support the requirements of upcoming headset generations. Instead, we describe a new generation of test equipment that integrates both "micro"- and "macro"-scale test capabilities in one instrument.

This conference presentation was prepared for SPIE AR | VR | MR, 2024.

This conference presentation was prepared for SPIE AR | VR | MR, 2024.

This conference presentation was prepared for SPIE AR | VR | MR, 2024.

This conference presentation was prepared for SPIE AR | VR | MR, 2024.

Despite several competing technologies for Augmented Reality (AR) displays, surface relief gratings are amongst the most promising solutions. While Reactive Ion Etching (RIE), failed to produce slanted trenches due to the lack of directional control, Reactive Ion Beam Etching (RIBE) is a technique well suited to fabricate theses gratings via a combination of physical and chemical etching processes and substrate tilting. Along with several advantages of RIBE over RIE, such as enhanced control of the slant angle, achieving full wafer etching with superior uniformity for static, off-normal incidence process conditions have remained a challenge. Veeco’s latest generation IBE source technology with multi-zone electromagnets is a proven solution to fabricate highly uniform blanket and patterned 200 mm wafers under static, off-angle conditions. Combining this technology with RIBE/IBE, we have created uniform off-angle featured wafers such as slanted gratings with different slanted angles (0-60˚) which is a critical approach in the AR applications.

Defects in master and replica waveguide gratings can cause image quality issues on AR displays. Characterizing these gratings is difficult due to their small features, which can be smaller than the wavelength of visible light. Microscopy is unsuitable for production testing as it lacks resolution and can be destructive. The authors propose an optical metrology setup using Littrow configuration to accurately measure diffraction grating pitch and orientation at a picometer and arcsecond scale to identify defects. The authors will also demonstrate the impact of grating analysis on the image quality of diffractive waveguides.

Explore the significant impact of alignment on the optical performance data and resulting technical specifications of augmented reality (AR) and virtual reality (VR) devices providing insights into the considerations necessary for optimal alignment strategies. The relevance of true eye geometry is highlighted in considering pupil rotation in instantaneous/wide field of view cameras compared to true eye rotation of the human eye as represented by an active gaze tracking and imaging platform.

Displacement Talbot Lithography (DTL) has emerged as a viable technology that relies on the proven photolithography approach of the semiconductor industry while offering a specific, low-cost solution for large area printing of periodic structures of the kind required on waveguides. Electronic Design Automation (EDA) tools are necessary for standard projection lithography approaches, and now can be used to understand DTL interactions with waveguide designs. Here, we present the first results from the development of a complete design and optimization approach that facilitates fabrication of waveguide devices with optimum processing conditions and targeted device performance.

In this paper, we present world-first TFT liquid crystal glasses (TFT-LCG) that display images to the passersby and have limited obstruction to the vision of wearers. By the concept of manipulating the polarization state of incident light with the liquid crystal, the appearance at the world side of the glasses is electrically controlled. The glasses display colored images with resolution of 36 pixels per inch and contrast ratio over 15. The viewing angle of wearer is almost the same as existing glasses and keep high MTF performance with TFT pixel traces. The driving power of the TFT-LCG is lower than 100mW with frame rate of 10 fps. Integrated with virtual platform and wireless control, the glasses can serve as a novel interaction medium between individuals. It opens a new path for how people connect with each other.