This work provides the design of a multifocal display that can create a dense stack of focal planes in a single shot. We achieve this using a novel computational lens that provides spatial selectivity in its focal length, i.e, the lens appears to have different focal lengths across points on a display behind it. This enables a multifocal display via an appropriate selection of the spatially-varying focal length, thereby avoiding time multiplexing techniques that are associated with traditional focus tunable lenses. The idea central to this design is a modification of a Lohmann lens, a focus tunable lens created with two cubic phase plates that translate relative to each other. Using optical relays and a phase spatial light modulator, we replace the physical translation of the cubic plates with an optical one, while simultaneously allowing for different pixels on the display to undergo different amounts of translations and, consequently, different focal lengths. We refer to this design as a Split-Lohmann multifocal display. Split-Lohmann displays provide a large étendue as well as high spatial and depth resolutions; the absence of time multiplexing and the extremely light computational footprint for content processing makes it suitable for video and interactive experiences. Using a lab prototype, we show results over a wide range of static, dynamic, and interactive 3D scenes, showcasing high visual quality over a large working range.

Spending time together and enjoying everyday activities helps to support interpersonal relationships, which have many positive benefits for individuals. However, many of these activities are difficult, if not impossible, to participate in when the relationship is long-distance. This work aims to address that problem with one such activity: watching videos together (or video co-watching). In this extended abstract we describe the user-centered design process we used to design our video co-watching web app. Specifically, we conducted semi-structured interviews with 10 individuals who watch videos with others to understand their current video watching activities. We analyzed those findings using affinity diagramming to identify user requirements and features. After sketching multiple wireframes and getting feedback, we developed an interactive prototype.