Convolutional neural networks are crucial for a variety of computer vision tasks, including object recognition, tracking, classification, and segmentation. However, the computational demands of these networks often result in substantial energy consumption and latency issues. Nanophotonic optical encoders, which leverage point spread functions acting as kernels, offer a solution by performing convolution in the optical domain. This innovative approach has led to over two orders of magnitude reduction in energy usage and four orders of magnitude improvement in latency, with ongoing efforts to expand its applications.

Compact, energy-efficient, and low-power optoelectronic devices can be realized through advancements in nanophotonics. (1) Flatband photodetectors achieve a compact form factor by integrating three optical elements—polarizer, color filter, and sensor—into a single thin layer of silicon p-i-n diode. (2) Chiral flatbands enable precise control of photodetectors sensitive to circularly polarized light. (3) Silicon nanobeam cavities support low-threshold lasing and significantly reduce power consumption in most optical systems.

Solid-state quantum light sources (e.g., quantum dots, defect centers) are promising due to their high brightness, robustness, and device compatibility. Their surrounding medium affects light extraction efficiency and coherence through dephasing. Nanophotonic cavities enhance radiative coupling rates and directional emission. Structures like nanoantennas and circular Bragg gratings have been coupled to site-controlled single quantum dots. Additionally, nanoscale luminescence quenching enables single quantum dot selection, addressing spatial and spectral inhomogeneity for scalable quantum optical platforms.

Photons are excellent information carriers due to their speed, ability to travel through a vacuum, minimal interaction, and versatile properties like wavelength and polarization. However, photonic systems face challenges in reconfigurability, which is often inefficient, slow, and significantly more complex compared to electronic systems. Phase-change materials offer nonvolatile reconfigurability, while liquid crystals provide polarization-based control. Advances such as resonance shifts in optical cavities and field-of-view adjustments in metalenses highlight the potential of these innovations. Triplet metasurfaces can further enhance metalens functionality by enabling zoom in-and-out capabilities.