Lasing in a photonic wire - semiconductor microcavity laser developed - Brief Article

Science News, June 10, 1995

Confining polarized photons to a microscopic "tube" in the shape of a ring can squeeze the light into a laser beam. Now, Seng-Tiong Ho of Northwestern University in Evanston, Ill., and his collaborators have constructed and demonstrated the first semiconductor microcavity laser based on this principle.

The researchers cage photons in a ring made of a gallium-arsenide-based material coated with silicon dioxide. Such an optical "wire" retains and guides photons despite tight curvature. The ring itself has a diameter of 4.5 micrometers and a width of 0.4 [mu]m.

Shining a pulse of light from an argon lamp on the ring injects photons, which circulate within the waveguide. These confined photons settle readily into a coordinated mode, turning the microcavity into a tiny laser considerably more efficient than conventional lasers.