South Korean Researchers Develop Ultra-Thin AR Glasses Technology
A South Korean research team has developed optical technology that makes augmented reality (AR) smart glasses as thin and lightweight as ordinary spectacles while continuing display clarity in bright outdoor conditions. The researchers seek to incorporate the technology into commercially available smart glasses within two to three years.
The Ministry of Science and ICT announced that a joint research team led by POSTECH Professor No Joon-seok and Samsung Research, part of Samsung Electronics, developed an ultra-thin optical system that significantly reduces light loss. The research findings were published in the international academic journal Nature.
AR glasses overlay digital images onto a person’s view of the real world. However, making glasses as thin as ordinary spectacles whilst maintaining sufficient display brightness has been challenging. The problem is particularly noticeable outdoors, where screens can become illegible. This happens because a significant portion of the light emitted by the small display is lost as it travels through the lens, reducing the brightness of the image reaching the eye.
Two years ago, the research team collaborated with Samsung Electronics to develop technology that displayed images using a single thin lens. However, the earlier system had a major limitation: screens visible indoors became invisible outdoors. To address this problem, the researchers redesigned the path light takes through the lens.
The central innovation uses metasurface technology, which involves precisely arranging nanoscale structures on a waveguide. The structures are far smaller than a human hair, while the waveguide transmits light along a specific path. Their arrangement is designed to maximise the amount of light reaching the eye, even when light changes direction multiple times within the lens. This helps reduce light loss during transmission.
The researchers also addressed colour distortion by overlapping layers that transmit red and green light with layers that transmit blue and green light. This arrangement reduces colour distortion in the images displayed through the optical system.
The optical component developed using this method measures just 1.5 millimetres thick when both layers are combined. This is approximately one-third the thickness of optical components used in existing AR glasses. The team also produced a prototype shaped like actual spectacles. The prototype demonstrated the ability to overlay white text onto the real-world view in bright outdoor conditions and colour images onto the same view indoors.
The technology also has possible applications in mass production. In April, Professor No’s team announced a nano-imprinting process that uses a mould engraved with nanoscale patterns to stamp lenses, similar to a printing press. The team achieved production speeds of more than 300 ultra-thin lenses per second using this technique. Applying the previously developed manufacturing process to the new optical technology is expected to make mass production feasible.
The technology could also be applied relatively quickly to existing AI glasses by replacing their optical components. Professor No identified this approach as a potential application and set a target of incorporating the technology into commercially available smart glasses within two to three years.
