Hyperspectral and multispectral imaging, used originally for Earth observation, see obvious uses in remote sensing for agriculture.  New holographic sensors use neural networks to detect bacteria colonies in water samples. Infrared imagers detect drought stress and insect infestations in crops, and ultraviolet lights purify water.

Photonic technologies don't stop with protecting the safety of our food—they're also being used to increase yields and lengthen growing seasons. LED lights are now a mainstay in greenhouses, and are even being used to grow crops in inhospitable places, like the Arctic and the International Space Station.

This issue of Photonics Focus is dedicated to the photonic technologies that keep our food safe and help ensure an agricultural production and distribution system that can feed more than nine billion people.