"Here, infrared imaging is demonstrated by nonlinear up-conversion to the visible in an ultra-compact, high-quality-factor lithium niobate resonant metasurface. Images with high conversion efficiency and resolution quality are obtained despite the strong nonlocality of the metasurface. The possibility of edge-detection image processing augmented with direct up-conversion imaging for advanced night vision applications is further shown."
Fourier features in learning systems like neural networks due to the downstream invariance of the learner that becomes insensitive to certain transformations, e.g., planar translation or rotation.
