In this work we investigate design parameters of a stereoscopic head-worn augmented reality display that would facilitate a wider uptake of technology by enterprise and professional users. The emphasis is put on mimicking a way of how naturally the ambient world is perceived by human visual system. To solve this, we propose a solid-state multi-focal display architecture, which is tailored for near-work oriented tasks. The core of the proposed technology is a solid-state multi-plane volumetric screen, with four physical image depth planes which form the secondary image source. The volumetric screen utilizes electrically controllable liquid-crystal based diffuser elements, which receive the image information from the primary source – a pico projection unit. The volumetric screen is coupled with a bird-bath type optical image combiner/eyepiece to yield a 40-degree horizontal field of view covering a representable depth space of 0.35m to infinity where no effects of vergence-accommodation conflict are experienced.
In the field of 3D display technologies for a long-time accommodation-based depth cues have been dismissed. On one hand they are treated as weak depth cues, but on other hand their inclusion has been technologically challenging. Either way, accommodation depth cues are essential in ensuring natural image perception; they add realism to the 3D scene and help overcoming technologically inhibiting effects of vergence-accommodation conflict. In this work we examine implementation and associated considerations of optical diffuser technology via spatial volume demultiplexer chip (SVDC) within a stereoscopic Augmented Reality (AR) wearable display. The role of SVDC is to demultiplex series of two-dimensional image depth planes into a perceivably three-dimensional scene with said focus depth cues. The SVDC chip is designed to be entirely solid-state solution, requiring only voltage driving signal for the image demultiplexing action. In case of using an SVDC for multi-plane display architecture, the image source is a rear image projection unit ensuring high refresh-rate stream of required 2D image depth planes. The SVDC technology is scalable, it facilitates improved light efficiency due to controlled internal reflections which allows for diverse optical design in AR as well as VR settings. Provided is indicative evaluation and comparison of different optical image combiner solutions in respect to using a SVDC display architecture for near-eye stereoscopic AR display systems. Considered designs of optical image combiners include flat beam splitter with a refractive eyepiece, “bird-bath” optics, and single curved (free-form) reflective image combiner.
In this work a detailed analysis of technologies and methods required for a construction and operation of passive multiplane volumetric 3D display based on the arrangement of electrically controllable optical diffuser elements has been provided. Current methods of displaying 3D images have been compared. Challenges and solutions of representing realistic looking 3D content with associated physical depth cues in regards to multi-plane approach have been highlighted. The main focus has been devoted to consideration of improving user experience when viewing and interacting with the 3D content on a multi-plane volumetric display by utilizing various task-specific computational methods in the data processing pipeline.
The study of direct recording of the surface relief gratings on amorphous chalcogenide thin (2.5 to 5 μm films is presented by three different recording setups. Recording was performed on As2S3 by 532-nm wavelength laser light. Additionally, the evolution of a surface relief in dependence from the recording time and polarization has been investigated in detail and for the first time, the mass transfer process has been explained from the point of view of the photoinduced birefringence. The role of photoinduced plasticity in the formation of surface relief in amorphous chalcogenides during holographic recording has been discussed.
In this report the study of direct recording of the surface relief gratings on amorphous chalcogenide thin (2.5-5μm) films is presented by three different recording setups. Recording was performed on As2S3 by 532nm wavelength laser light. Additionally the evolution of surface relief in dependence from the recording time and polarization has been investigated in detail. The mechanism of the direct recording of surface relief on amorphous chalcogenide films based on the photo-induced plasticity has been discussed.