Metamaterial and Plasmonic Devices Group
The Metamaterial and Plasmonic Devices Group, lead by Prof. Humeyra Caglayan.
Our group focuses on engineering the fundamental interaction between light and matter and applying this understanding to light trapping, energy collection and extraction, communication, and sensor applications. These studies involve novel photonic and plasmonic structures, and quantum materials; with reduced dimensions, improved performances, and novel optical and photonic functionalities.
Tunable Metamaterials and plasmonic devices
It is possible to tailor the metamaterials and plasmonic devices by changing the fabricated dimensions. However, these approaches are lack of real-time control. The ability to tune the resonance wavelength will enable the real-time control of the devices and add more functionality.
We currently work on metamaterial based optical nanocircuits. We fabricate ITO nanorod structures which act as optical RLC nanocircuits and add more functionality to the metatronic nanocircuits changing the dielectric constant of the gap region dynamically. The capacitance value of optical nanocircuits changes when the dielectric constant of the gap region the nanoscale gap region changes. We have changed the resonance of the metatronic circuit by the control of the outside medium. We tuned the optical element values by changing the substrate filling the nanoscale gap region in real-time. Finally, we have tested these metamaterial based devices as biosensors.
Epsilon-Near-Zero (ENZ) metamaterials
Recently, metamaterials with epsilon near zero metamaterials have attracted much attention. Light inside these materials experiences no spatial phase change and extremely large phase velocity, makes these peculiar systems applicable for realizing directional emission, tunneling waveguides, large-area single-mode devices and electromagnetic cloaks.
We study enhanced transmission/emission through an aperture and beam its extraction using an ENZ metamaterial. Funneling electromagnetic energy through a subwavelength aperture that is covered with epsilon-near-zero metamaterials has been obtained.
Additionally, we propose a simple but powerful medium for quantum information processing and communication consisting of a zero-index photonic crystal (PC) waveguide (WG). By exploiting the zero-index behavior of the PC WG, we overcome the diﬃculty of sensitivity in quantum dots’ location, which is one of the main challenges for preparing and measuring a two- qubit entangled state.
Graphene and similar 2D crystal based nanophotonic devices
Graphene is a 2D material that consists of carbon atoms arranged in a honeycomb lattice. It has been a promising material for electro-optic devices due to various remarkable properties.
We investigated graphene-gold plasmonic structures to enhance light-graphene interaction.
We also electrically control these devices. We believe that this approach could lead to new applications ranging from electrically switchable clocking devices to adaptive camouflage systems in microwave and terahertz frequencies.
Quantum plasmonics and quantum metamaterials
We will not only obtain enhance and directional emission but also change emission lifetime and emission rate using novel plasmonic nanostructures and metamaterials such as Hyperbolic Metamaterials (HMM). These structures provide efficient interaction of light and enable the development of plasmonic based novel nanolasers and single photon sources. We will also investigate spontaneous emission enhancement by exciton-plasmon coupling using these structures.
We will investigate the emission of quantum emitters embedded in an ENZ medium. It is possible to investigate coherence length and superradiance using ENZ medium integrated with quantum emitters such as nanodiamond NV centers. We are also interested in applying fascinating ENZ features to different platforms such as 2D materials.