Software and Hardware Enabling the Next-Generation Near-Eye Displays

In the last decade augmented and virtual realities have become topics of great interest in academia, industry, and the popular media. Despite their popularity, head-worn displays have not yet become a widely adopted technology. The “holy grail” of the field is a light, compact wearable device that can enable exciting consumer applications with realistic graphics. To provide high-fidelity user experience, it is required for the device to have a high optical performance display engine fitting in the desired form factor. The realization of this type of display, however, is a great engineering challenge due to the inherent tradeoff between optical performance and the size of the optical components. Novel software and hardware are required to expand the optical design and fabrication space, thus enabling the next generation of near-eye displays. In the current research, we leverage two main optical technologies that can provide an engineered wavefront response in a compact form–freeform optics and metasurfaces. We also explore the development of a research centered optical design platform that can enable the incorporation of these technologies in the design of near-eye displays. Any optical component used in consumer technology needs to be durable. We propose a method for protecting plasmonic metasurfaces using thin (tens of nanometers) dielectric coatings. We successfully demonstrate this concept by designing, fabricating, and testing a plasmonic reflective metasurface grating with a PMMA coating. A time-lapse experiment over nearly two years is performed, verifying that the grating efficiency of the device does not significantly decrease over time when kept in normal room temperature and humidity. Plasmonic reflective metasurfaces are intrinsically opaque. To enable the use of these metasurfaces in a combiner of a see-through near-eye display, we propose the use of arrays of apertures with random position and diameter. A dual-function device for use with visible illumination is created. The device diffracts light in reflection, while in transmission it passes 50% of the incident illumination with minimal diffraction artifacts. The device grating efficiency in reflection, the see-through capabilities, and its behavior under bright illumination are all experimentally verified. A new type of optical surface, a metaform, is then introduced as a metasurface conformed to a freeform optics. We establish the design principles of a metaform and apply them to the design of a miniature imager using a single metaform. An enhanced electron beam lithography process on a freeform (curved) substrate is used to fabricate the metaform. The miniature imager is then assembled, and its imaging performance is tested experimentally. Finally, we introduce Eikonal+–a research software platform for 3D optical design. Eikonal+ is currently being developed at The Institute of Optics with the vision of a design platform that can enable the integration of novel optical components, such as metasurfaces, freeform optics, and metaforms for research in optical system design. The software evolution from a legacy Fortran code to a cross-platform computational engine is detailed. We also introduce Hyperion–the 3D visualization platform supported by Eikonal+. Various prototypes of Hyperion on Windows, mobile devices, and Oculus Rift are demonstrated. The current HoloLens enabled Hyperion is presented in conclusion