| Efficient confinement of the optical field to nanometer dimensions will enable an entire new class of low power optical devices. The range of devices that could be created is staggering. In addition to greatly enhancing microscopy and optical lithography, such an advance would allow for optical non-linearities with only a few photons. While the technological impetus is great, there is currently no device in the prior art which can achieve nanoscale optical focusing with any degree of efficiency. This dissertation presents the analysis and simulation of a novel plasmonic lens which can confine the optical field with astonishing efficiency. The key to the function of the device is the use of surface plasmons in a Metal-Insulator-Metal slab geometry. The unique dispersion of these modes allows for very large wave-vectors, achieving X-ray wavelengths with visible frequencies. This effect is exploited to achieve enhancements of the square of the electric field which are greater than 105 compared to that of the focus of a microscope objective. Through the use of extensive analysis and electromagnetic simulations, this novel device is demonstrated to have less than 10dB of loss when focusing the field of a visible photon to 3nm by 7nm. |
