Polychromatic Dual-Mode Imaging with Structured Chiral Photonic Crystals

Abstract

Optical spatial differentiation is a typical operation of optical analog computing and can single out the edge to accelerate the subsequent image processing, but in some cases, overall information about the object needs to be presented synchronously. Here, we propose a multifunctional optical device based on structured chiral photonic crystals for the simultaneous realization of real-time dual-mode imaging. This optical differentiator is realized by self-organized large-birefringence cholesteric liquid crystals, which are photopatterned to encode with a special integrated geometric phase. Two highly spin-selective modes of second-order spatial differentiation and bright-field imaging are exhibited in the reflected and transmitted directions, respectively. Two-dimensional edges of both amplitude and phase objects have been efficiently enhanced in high contrast and the broadband spectrum. This work extends the ingenious building of hierarchical chiral nanostructures, enriches their applications in the emerging frontiers of optical computing, and boasts considerable potential in machine vision and microscopy.

Switchable Two-Dimensional AND and Exclusive OR Operation Based on Dual-Wavelength Metasurfaces

“…Recently, meta-based integration, , differentiation, , convolution, and other mathematical computation functions have been successfully implemented. Leveraging the strong computing capability, metasurfaces proficiently process optical images, covering tasks like edge detection, − pattern recognition, − and equation solving. , Apart from arithmetic operations, logic operations are also essential foundational concepts in data processing, and numerous microscale optical logic processors have been reported. − In image processing, two-dimensional logic operations offer an effective means of comprehending the visual world by revealing hidden insights and enhancing image readability. Among various logic operations, the AND and XOR operations are noteworthy because of their ability to extract common and differential components of images.…”