Nanowerk August 11, 2020
Due to the diffraction limit seeing and recognizing an object whose size is much smaller than the illumination wavelength is a challenging task for an observer placed in the far field. Researchers in Switzerland have demonstrated that combining deep learning with lossy metalenses allows recognizing and imaging largely subwavelength features directly from the far field. Their acoustic learning experiment shows that, despite being 30 times smaller than the wavelength of sound, the fine details of images can be successfully reconstructed and recognized in the far field, which is crucially favored by the presence of absorption. They envision applications for this technique in acoustic image analysis, feature detection, object classification, or as a novel noninvasive acoustic sensing tool in biomedical applications…read more. Open Access TECHNICAL ARTICLE
Illustration of the experimental setup. (Image: EPFL)