Medical researchers from Harvard University have created the first “living laser”; a biological cell that’s been genetically engineered to produce a visible laser beam.

Lasers need two things to generate beams. They need a gain medium that amplifies light, and an arrangement of mirrors to concentrate and align that light.

Normal lasers, ever since their invention in the 1950s, use synthetic gain materials like gases, crystals and dyes to amplify photon pulses. But professor Seok-Hyun Yun and colleague Malte Gather, instead used green fluorescent protein (GFP), which is used to make jellyfish bioluminescent, as their gain material.

via ‘Living Laser’ Engineered From Human Cells | Wired Science | Wired.com.