Mar 4 2010
Semiconductor microcavity lasers are attractive as building blocks for nanophotonics applications, such as optical switches, sensors and ultrasmall light sources for optical computing, but their successful integration hinges on the efficient extraction of the light energy therein.
This efficiency could be increased significantly by applying an external magnetic field to elliptically shaped microcavities, according to the results of a numerical study by Eng Huat Khoo and co-workers from the Institute of High Performance Computing, A*STAR, Singapore.
When electrons are trapped in microscale cavities, quantum physics dictates that they can only assume certain discrete energies. This energy ‘quantization’ is beneficial when incident light is trapped along with the electrons because, under the right circumstances, their mutual interaction produces highly efficient monochromatic laser light following transitions between the well-defined energy levels within the cavity.
The laser light can be extracted from the cavity by placing an optical waveguide adjacent to it. At an optimum distance, photons—the basic ‘unit’ of light—can jump from the cavity to the waveguide via quantum mechanical tunneling.
Click here to read the full story.