SEMINAR: Physics Seminar

Conventional antennas, which are widely used to transmit radio and TV signals, can be used at optical frequencies as long as they are shrunk to nanometer-size dimensions. Optical nanoantennas possess plasmonic modes – collective oscillations of the metal's conduction electrons – that strongly enhance the coupling between light and nanoantenna and allow for manipulating light on a scale smaller than light's wavelength. Based on this ability, optical nanoantennas offer unique opportunities regarding key applications such as optical communications, photovoltaics, non-classical light emission, and sensing. From a multitude of suggested nanoantenna concepts the Yagi-Uda nanoantenna, an optical analogue of the well-established radio-frequency Yagi-Uda antenna, stands out by its efficient unidirectional light emission and enhancement.

Following a brief introduction to the emerging field of optical nanoantennas, the first part of the talk will review our recent activities on optical Yagi-Uda nanoantennas and discuss several extensions of the conventional Yagi-Uda antenna design for broadband and tunable operation for applications in nanophotonic circuits, solar cells and nanosensors.

The second part of the talk will discuss novel optical nanoantennas proposed as integrated sources of nonclassical light. We demonstrate theoretically that these nanoantennas ensure both a large broadband spontaneous emission enhancement and high collection efficiency for horizontally and vertically polarized photons emitted by a semiconductor quantum dot. The suggested nanoantenna designs make a step forward toward reliable, efficient and on-chip integrable sources of polarization entangled photons for a variety of quantum applications.

Dr. Ivan Maksymov received his PhD from Kharkov National University of Radio Electronics (Ukraine) in 2008, where he later held the positions of Lecturer and Assistant Professor. Afterwards he took a postdoc position at Institute of Optics (Palaiseau, France) where he worked on plasmonic sources of nonclassical light. Currently, he is a postdoctoral fellow at the Nonlinear Physics Centre, ANU working on theory of optical nanoantennas.