ABSTRACT
This chapter provides the introduction of optical antennas, their comparison with radio frequency antennas, the surface plasmonic resonance excitation in optical antennas, the near-field profiles and enhancement, directional gains, and far-field detection and patterns. It discusses the applications of the plasmonic optical antennas in infrared photodetection. The chapter presents a couple of optical antenna enhanced quantum dot IR photodetectors (QDIPs) with their near-field analysis and polarization and receiving pattern measurements. The excitation of surface plasmonic waves in optical antennas can not only change the near-field distribution but also greatly enhance the near fields at the plasmonic resonant wavelengths. The polarization dependence of the optical antenna enhanced QDIP was measured using a Bruker Tensor 27 Fourier Transform Infrared Spectrometer. The near fields are analyzed for a pointed dipole optical antenna and compared with the photodetector enhancement. The chapter analyzes the transformation between the far field and near field of a pointed dipole optical antenna.
