Isotropic Topological Second-Order Spatial Differentiator Operating in Transmission Mode

Abstract

Differentiation has widespread applications, particularly in image processing for edge detection. Significant advances have been made in using nanophotonic structures and metamaterials to perform such operations. In particular, a recent work demonstrated a topological differentiator in which the transfer function exhibits a topological charge, making the differentiation operation robust to variation of operating conditions. The demonstrated topological differentiator, however, operates in the reflection mode at off-normal incidence and is difficult to integrate into compact imaging systems. In this work, we design a topological differentiator that operates isotropically in transmission mode at normal incidence. The device exhibits an optical transfer function with a symmetry-protected, topological charge of $\pm 2$ and performs second-order differentiation. Our work points to the potential of harnessing topological concepts for optical computing applications.

arXiv comment5 pages, 5 figures

References in corpus (5)

• Generalized spatial differentiation from spin Hall effect of light
• A Photonic Crystal Slab Laplace Differentiator
• Meta-optics for spatial optical analog computing
• First-order optical spatial differentiator based on a guided-mode resonant grating
• Optical spatial differentiation with suspended subwavelength gratings

Cited by in corpus (5)

• Polarization-independent isotropic nonlocal metasurfaces with wavelength-controlled functionality
• Unitary control of partially coherent waves. II. Transmission or reflection
• Topological winding guaranteed coherent orthogonal scattering
• Polarization-independent optical spatial differentiation with a doubly-resonant one-dimensional guided-mode grating
• Joint control of coherent transmission, reflection, and absorption