Nonlinear Plasmonic Devices

Over the past fifty years, technological advancements in the microelectronics industry have been astounding. As a result of this success, today’s microfabricated devices are inexpensive, can be produced in large volumes, and can be fabricated with billions of sub-100 nm logic elements as small area microchips. Further increases in computational density will require even more innovation, as fundamental limitations in semiconductor lithography are approached. One strong candidate for continued miniaturization is the integration of optical signals with electronics at the transistor level. It is widely believed that the complete integration of electronics and photonics on a sub-micron scale will be accomplished in the near future. Optical signals offer an almost unlimited bandwidth and low loss, and therefore, it is highly desirable to couple optics and electronics at the wafer level to develop novel logic device architectures. However, the natural spatial scale of light determined by its diffraction is at least an order of magnitude larger than that of a typical electronic component (e.g., a transistor). As a consequence, diffraction of light is the major obstacle to a variety of applications requiring concentrating optical energy in a small volume: light simply cannot be confined to dimensions much smaller than half of its wavelength. To fulfill the need for such a device, Nanohmics Inc. and Drs. Gennady Shvets and Alex Demkov at The University of Texas at Austin propose to develop an optically gated Ponderomotive Effect Transistor (PET) consisting of a plasmonic antenna placed in the gate area. The plasmonic antenna concentrates the intensity of the otherwise broadly focused laser beam in the gate region and locally modifies the band structure of the electrons and holes.