Room-temperature subwavelength metallo-dielectric lasers

We demonstrate room-temperature pulsed laser emission from optically pumped metallo-dielectric cavities that are smaller than their emission wavelength in all three dimensions. The cavity consists of an aluminium/silica bi-layer shield surrounding an InGaAsP disk in which the thickness of the silica layer is optimized to minimize the gain threshold of the laser. The lasers are pumped using a 1,064-nm pulsed fibre laser with a pulse width of 12 ns and repetition rate of 300 kHz. Lasing emission at 1.43 mu m is observed from a laser with slightly elliptical gain core with major and minor diameters of 490 and 420 nm, respectively. Owing to the isolation provided by the aluminium shield, this laser design approach can be used to create arrays of uncoupled lasers with emitter densities that are close to the Rayleigh resolution limit.