Yale physicists invented an anti-laser that absorbs light—key to optical switching.
Professor Douglas Stone and colleagues at Yale University had been developing a theory to explain which materials could be used as the basis of lasers.
That theory predicted that instead of amplifying light into coherent pulses, as a laser does, it should be possible to create a device that absorbs laser light hitting it—an anti-laser.
Their device focuses two lasers beams of a specific frequency into a specially designed optical cavity made from silicon, which traps the incoming beams of light and forces them to bounce around until all their energy is dissipated.
In a paper published in the journal Science they demonstrated that the anti-laser could absorb 99.4 per cent of incoming light, for a specific wavelength.
The anti-laser's big advantage is that it is built using silicon, which is already widely used in computing.