|Ph.D Thesis||Department of Electrical Engineering|
|Supervisor:||Prof. Orenstein Meir|
|Full Thesis text|
The nowadays challenges in micro-electronics and photonics are partially directed to increase the speed of devices and reduce their physical dimensions and operation power. The current micro-electronic technology achieved significant progress in high-scale integration and miniaturization reaching the dimensions of electron de Broglie wavelength. However, the modulation speed of electronic components is rapidly approaching the electronic bottleneck accompanied by increased power dissipation. On the other hand, photonic components may operate in dozens of THz frequency range with negligible power losses, however the miniaturization of photonic circuits is virtually limited by diffraction to the scale of optical wavelengths.
Here we investigate the possible interface between electronic components and photonic devices, based on plasmonic circuits, and one of their important applications - metamaterials.
Dielectric-metal interface supports surface waves called Surface Plasmon Polaritons (SPPs). SPPs are not obeying diffraction limit of light, and may be confined on the nano-scale. We demonstrated both theoretically and experimentally the nano-confinement of visible and infrared light in various configurations: waveguide tapering, downscaled radio-frequency-like quarterwavelength transformers, nano-needles excited by plasmonic planar lenses, and pairs of coupled nano-antennas. Fundamental limits of plasmonic confinement were tested along with the investigation of a new type of inherent ponderomotive nonlinearity. New types of plasmonic particles with widely-tunable resonances were investigated together with a new algorithm for the generation of optimal particle shapes. Such particles may serve as building blocks for new materials - metamaterials.
Metamaterials are artificial electromagnetic multi-functional materials engineered to satisfy the prescribed requirements. One of the outstanding examples is materials with negative refraction index. Our original proposal is to incorporate quantum structures such as quantum wells, wires and dots as inclusions. We demonstrate theoretically all-semiconductor tunable low-loss negative-index metamaterials based on coupled quantum wells and dots and quantum-cascade based active plasmonics. Moreover, we proposed electrically-controlled metamaterials for light slowing and phasematching in nonlinear optics. Incorporation of active elements within metamaterials may not only significantly improve their performances, but also lead to investigation of very efficient sources of radiation, for example, entanglement. We theoretically proposed and experimentally demonstrated a novel process of semiconductor two-photon emission. The basic phenomenon, incorporated with photonic structures, such as Bragg and photonic crystal cavities may lead to the generation of entangled and hyper-entangled photon pairs. Coherently controlled semiconductor structures were proposed to detect such states, and together with the novel sources they open new horizons for all-semiconductor room-temperature quantum communication technologies.