Full‐Color and Polarimetric Edge Imaging Under Incoherent Illumination With Inverse‐Designed Photonic Crystals

Analog optical computation has attracted increasing attention due to its ultrafast processing speed and low power consumption. However, all the conventional methods are constrained by either narrow spectral bandwidth, the requirement of coherent illumination or complicated system, which significantly limits their applicability in practical scenarios. Here, we present a broadband full‐color and polarimetric spatial differentiation under incoherent natural illumination across the entire visible spectrum with an inverse‐designed one‐dimensional photonic crystal. By harnessing polarization‐dependent responses of the photonic crystal of alternative SiO 2 /TiO 2 layers, a specific polarization‐dependent response in k ‐space can be obtained, from which the difference between optical transfer functions of arbitrary linear polarization and its corresponding orthogonal exhibits a linear dependence on the incident angle under incoherent illumination across the entire visible spectrum. Experiments with both microscopic and telescopic imaging systems show excellent colorful and spectral edge images under natural light illuminations in contrast to the black/white images in all those conventional narrow‐bandwidth methods. This proposed approach enables both spectral edge imaging and polarimetric edge imaging and also effectively addresses the longstanding limitations of bandwidth, efficiency, and coherence in edge imaging, paving the way for the development of robust, broadband analog optical processors suitable for large‐aperture and real‐world applications.