OPTICAL ANTENNAS

The antennas are the enabling technology in satellite communication, cellular phones and other devices that uses electromagnetic radiation. An optical antenna is a device that powerfully couples the energy of free-space radiation to a restrained area of sub wavelength size. Optical antennas are a solution to the mismatch between the small dimensions of nanometer scale devices and the length scale related with optical wavelengths. While antennas are pervasive in the radio wave and microwave system they are essentially uncharted at optical frequencies. Optical antennas can amplify signals by a million times or more using lasers to induce quantum tunneling. The optical antennas are using both top down approach and bottom up approach. The optical antennas are used to efficiently increase the quantum yield of the devices. An optical antenna focuses radiation to sub wavelength dimensions but it also cooperates with the system under exploration. This can be done by measuring the deflection of a cantilever with an attached particle. With this approach we can measure the field enhancement factor and also optimize the properties of the optical antennas in the iterative method. The optical antenna arrays can be used for increasing the efficiency of optoelectronic devices and biochemical sensors.