Metallic nano-cavity lasers at near infrared wavelengths

There has been considerable interest in nano-cavity lasers, both from a scientific perspective for investigating fundamental properties of lasers and cavities, and also to produce smaller and better lasers for low-power applications. Light confinement on a wavelength scale has been reported in photonic crystal nano-cavities. Even stronger light confinement can be achieved in metallic cavities which can confine light to volumes with dimensions considerably smaller than the wavelength of light. It was commonly believed, however, that the high losses in metals are prohibitive for laser operation in metallic nano-cavities. Recently we have reported lasing in a metallic nano-cavity filled with an electrically pumped semiconductor. Importantly, the manufacturing approach employed for these devices permits even greater miniaturization of the laser. In particular Metal-Insulator-Metal (MIM) waveguides with dimensions well below the diffraction limit can be fabricated using our techniques. Experimental results from such MIM waveguide lasers will be presented. In theory it is shown that it is possible to reduce the semiconductor gain medium dimensions of these MIM waveguide devices down to a few tens of nanometers in size. Finally, latest results for the fabrication of MIM type waveguide devices will also be examined.