Browsing by Subject "Transmission response"

Now showing 1 - 2 of 2

Open Access
Enhanced tunability of V-shaped plasmonic structures using ionic liquid gating and graphene
(Elsevier Ltd, 2016) Ozdemir, O.; Aygar, A. M.; Balci, O.; Kocabas, C.; Caglayan, H.; Özbay, Ekmel
Graphene is a strong candidate for active optoelectronic devices because of its electrostatically tunable optical response. Current substrate back-gating methods are unable to sustain high fields through graphene unless a high gate voltage is applied. In order to solve this problem, ionic liquid gating is used which allows substrate front side gating, thus eliminating the major loss factors such as a dielectric layer and a thick substrate layer. On the other hand, due to its two dimensional nature, graphene interacts weakly with light and this interaction limits its efficiency in optoelectronic devices. However, V-shaped plasmonic antennas can be used to enhance the incident electric field intensity and confine the electric field near graphene thus allowing further interaction with graphene. Combining V-shaped nanoantennas with the tunable response of graphene, the operation wavelength of the devices that utilize V-shaped antennas can be tuned in situ. In the present paper, we demonstrate a graphene-based device with ionic liquid gating and V- shaped plasmonic antennas to both enhance and more effectively tune the total optical response. We are able to tune the transmission response of the device for up to 389 nm by changing the gate voltage by 3.8 V in the mid-infrared regime.
Open Access
Photonic magnetic metamaterial basics
(Elsevier, 2010-07-21) Alici, K. B.; Serebryannikov, A. E.; Özbay, Ekmel
In the present study, we provide a detailed analysis for the study of photonic metamaterials. We demonstrate the polarization and orientation dependent transmission response of split ring resonators at the infrared and visible band. We provided optical measurements only for one case, in which electric component of the incident field was coupled to planar split ring resonator array. We consecutively studied (i) frequency tuning, (ii) effect of resonator density, (iii) shifting magnetic resonance frequency by changing the resonator shape, and (iv) effect of metal loss and plasma frequency. The study provides an overlook for the candidate applications such as the enhancement of power passing through an electrically small hole, negative index metamaterials and optical metamaterial absorbers.