"Researchers at Columbia Engineering's Lipson Nanophotonics Group have created visible lasers of very pure colors from near-ultraviolet to near-infrared that fit on a fingertip"

High-performance visible-light lasers that fit on a fingertip (phys.org)

"In order to move forward, we have to be able to miniaturize and scale these systems, enabling them to eventually be incorporated in mass-deployed technologies," said Lipson, a pioneer in silicon photonics whose research has strongly shaped the field from its inception decades ago, with foundational contributions in the active and passive devices that are part of any current photonic chip. She added, "Integrated photonics is an exciting field that is truly revolutionizing our world, from optical telecommunications to quantum information to biosensing."

Thanks to Fazolac on Reddit for the link