Analog spatial differentiation is used to realize edge-based enhancement, which plays an important role in data compression, microscopy, and computer vision applications. Here, a planar chip made from dielectric multilayers is proposed to operate as both first- and second-order spatial differentiator without any need to change the structural parameters. Third- and fourth-order differentiations that have never been realized before, are also experimentally demonstrated with this chip. A theoretical analysis is proposed to explain the experimental results, which furtherly reveals that more differentiations can be achieved. Taking advantages of its differentiation capability, when this chip is incorporated into conventional imaging systems as a substrate, it enhances the edges of features in optical amplitude and phase images, thus expanding the functions of standard microscopes. This planar chip offers the advantages of a thin form factor and a multifunctional wave-based analogue computing ability, which will bring opportunities in optical imaging and computing.

Analog spatial differentiation is used to realize edge-based enhancement, which plays an important role in data compression, microscopy, and computer vision applications. Here, a planar chip made from dielectric multilayers is proposed to operate as both first- and second-order spatial differentiator without any need to change the structural parameters. Third- and fourth-order differentiations that have never been realized before, are also experimentally demonstrated with this chip. A theoretical analysis is proposed to explain the experimental results, which furtherly reveals that more differentiations can be achieved. Taking advantages of its differentiation capability, when this chip is incorporated into conventional imaging systems as a substrate, it enhances the edges of features in optical amplitude and phase images, thus expanding the functions of standard microscopes. This planar chip offers the advantages of a thin form factor and a multifunctional wave-based analogue computing ability, which will bring opportunities in optical imaging and computing.

Single-particle tracking (SPT) is an immensely valuable technique to study a variety of processes in the life sciences and condensed matter physics. Interferometric scattering (iSCAT) microscopy is a sensitive SPT technique that can track individual unlabeled particles with high spatial and temporal resolution. A difficulty in iSCAT is the low imaging contrast of its original image, and complicated imaging postprocessing method is necessary for deriving axial-location of the particle. Here, a planar photonic chip enhanced spin-to-orbital angular momentum conversion was introduced to the iSCAT microscopy, resulting in an axial-localization dependent double-helix point-spread-function (PSF) and high imaging contrast. This provides a new mechanism for 3D SPT over an extended axial-range in a label-free manner without use of complicated image postprocessing and optical components. The iSCAT microscopy was used to record the 3D trajectory of microbead labeled to the flagellum, facilitating precise analysis of the fluctuation in the motor dynamics. The enhanced iSCAT technique holds great promise for future applications in biological science.