Single planar photonic chip with tailored angular transmission for multiple-order analog spatial differentiator

Abstract

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.

All‐Optical Multiplexed Meta‐Differentiator for Tri‐Mode Surface Morphology Observation

“…It is known that both the 1 st ‐ and 2 nd ‐order differentiation can be used for edge detection. [ 44 ] However, for tiny objects, e.g., biological tissues, the edge is hard to be precisely positioned by the 1 st ‐order differentiation, since the structures of biological tissues are both small and complex. Hence, the 2 nd ‐order differentiation can be applied to further position the edge of biological tissues, since it is more sensitive to the fluctuation of surface morphology.…”

All-optical object identification and three-dimensional reconstruction based on optical computing metasurface

“…In practical applications, metasurfaces have shown the ability to efficiently manipulate several parameters of light, such as its phase 23,24 and polarization state 25−27 . As a result, metasurfaces are employed in numerous potential fields, such as optical analog computing 12,28−32 , optical cryptography 33−35 , optical devices designing 36,37 , signal manipulation 38,39 , microscopy imaging 40 , optical imaging 14,41−44 , and nanopainting 45 . Inspired by recently introduced optical analog computing and metasurface, we design and fabricate an optical computing metasurface that promotes development in imaging processing and 3D reconstruction.…”

Polychromatic Dual-Mode Imaging with Structured Chiral Photonic Crystals

“…This second-order spatial differentiator can highlight the phase mutation points of the firstorder derivative and serves as a more sensitive indicator of object variation, which has great potential in more accurately tracking edges and revealing new fine details. 39,40 In conclusion, we propose and demonstrate an innovative optical differentiator that uses structured chiral photonic crystals. The carefully designed integrated phase profile is encoded into self-assembled CLCs by photopatterning.…”

“…The CLC spiral phase plate operates the first-order differentiation by enhancing just one intensity maximum in the neighborhood of the phase edge, while the proposed CLC device (Figure d) produces two adjacent intensity maxima near the phase edge, corresponding to second-order differentiation. This second-order spatial differentiator can highlight the phase mutation points of the first-order derivative and serves as a more sensitive indicator of object variation, which has great potential in more accurately tracking edges and revealing new fine details. , …”