Baoqi Shi

A light beam sent from Earth to a satellite scatters in the atmosphere, like a flashlight in fog. To keep the signal intact, you need short-wavelength light that spreads less. Such light is born in special crystals, but shrinking them to chip size is tough.

Infrared light with a wavelength of about three micrometers is the working range for identifying molecules: each molecule absorbs light at its own characteristic frequencies, leaving behind "fingerprints." But until now, instruments for this range could not simultaneously provide broad frequency coverage, sufficient power, and…