Phys.org October 31, 2018
In metasurface-based optical systems, most of the total volume inside the device is just free space through which light propagates between different elements. Free space makes it difficult to scale down the device. To overcome this limitation, a team of researchers in the US (Caltech, UMass Amherst) has introduced a technology called “folded metasurface optics,” which is a way of printing multiple types of metasurfaces onto either side of a substrate making the substrate itself a propagation space for the light. They demonstrated the technique by building a spectrometer. The folded metasystem design can be applied to many optical systems, such as optical signal processors, interferometers, hyperspectral imagers, and computational optical systems, significantly reducing their sizes and increasing their mechanical robustness and potential for integration…read more. Open Access TECHNICAL ARTICLE
An array of 11 metasurface-based optical spectrometers, pictured here before the final fabrication step. Each spectrometer is composed of three metasurfaces that disperse and focus light with different wavelengths to different points. Credit: Faraon Lab/Caltech