Visible-Light Lasers That Fit on a Fingertip

Despite its success, integrated photonics has been missing a key component to achieve complete miniaturization: high-performance chip-scale lasers. While some progress has been made on near-infrared lasers, the visible-light lasers that currently feed photonic chips are still benchtop and expensive. Since visible light is essential for a wide range of applications including quantum optics, displays, and bioimaging, there is a need for tunable and narrow-linewidth chip-scale lasers emitting light of different colors.