Lasing from Escherichia coli bacteria genetically programmed to express green fluorescent protein.

We report on lasing action from colonies of Escherichia coli bacteria that are genetically programmed to synthesize the green fluorescent protein (GFP). When embedded in a Fabry-Perot type cavity and excited by ns-pulses of blue light (465 nm), the bacteria generate green laser emission (∼520 nm). Broad illumination of pump light yields simultaneous lasing over a large area in bacterial colonies.