An anonymous reader cites a report from Ars Technica. Facial recognition is a common feature used to unlock smartphones and gaming systems. However, this technology currently relies on bulky projectors and lenses, which prevents broader application. Scientists have now developed a new facial recognition system that uses flatter, simpler optics that requires less energy, according to a recent paper published in the journal Nano Letters. The researchers tested their prototype system using his 3D replica of Michelangelo's famous David statue and found that it was able to recognize faces similar to existing smartphone facial recognition. […]
Wen-Chen Hsu and colleagues at National Yangming Jiaotong University and Hong Hai Research Institute in Taiwan looked to ultra-thin optical components known as metasurfaces as a potential solution. These metasurfaces can replace bulky components for modulating light and have proven popular in depth sensors, endoscopy, and tomography. Augmented reality systems, among other emerging applications. Hsu et al. has built a unique depth-sensing facial recognition system that incorporates his holograms as metasurfaces instead of diffractive optical elements. They replaced the standard vertical cavity surface emitting laser (VCSEL) with a photonic crystal surface emitting laser (PCSEL). (Photonic crystal structures are the mechanism behind the bright iridescent colors of butterfly wings and beetle shells.) PCSELs are used in VCSELs because they can produce unique, highly collimated beams of light. No bulky light guides or collimating lenses were required. Base dot projector system.
The researchers tested the new system on a replica of David's bust and found it worked similarly to existing smartphone facial recognition, based on a comparison of the infrared dot pattern and an online photo of the statue. They found that their system produced nearly 1.5 times more infrared dots (approximately 45,700) than standard commercial technology from a device with a surface area 233 times smaller than a standard dot projector. “This is a compact and cost-effective system that can be integrated into a single chip using the PCSEL flip-chip process,” the authors wrote. Additionally, “metasurfaces enable the generation of customizable and versatile light patterns, increasing the applicability of the system.” It's more energy efficient to boot.