Tunable split-ring resonator for metamaterials using photocapacitance of semi-insulating GaAs

Abstract

We report a method for tuning a split-ring resonator (SRR) using infrared light. The SRR unit cells are commonly used in arrays to form a metamaterial that exhibits an effective negative permeability and are often used in negative-refractive-index materials. The region of negative permeability is generally limited to a narrow bandwidth at a fixed frequency. In this work, we use photocapacitance as observed in undoped semi-insulating GaAs to modify the gap capacitance of a SRR. We demonstrate a continuously tunable frequency over the range of 0.1–1.5 GHz using a 975 nm laser diode with a power range of 0–189 mW.

Frequency tunable terahertz metamaterials using broadside coupled split-ring resonators

“…This includes modification of the substrate parameters (e.g. permittivity) [4,5], the use of liquid crystals [6][7], lumped capacitors or varactors [8][9][10][11][12], ferromagnetic [13,14] and ferroelectric [15,16] techniques, semiconductors [17][18][19], microelectromechanical (MEMS) switches [20][21][22], and tuning based on near-field interactions between adjacent SRRs [23][24][25][26][27]. This last approach is the topic of the present study.…”

Magnetically tunable non-reciprocal plasmons resonator based on graphene-coated nanowire

“…Ring resonators have been extensively studied and shown to possess distinct functionalities in integrated optics on a variety of platforms, such as semiconductors [5], high index contrast dielectric waveguide [6] and metal-insulator-metal (MIM) waveguides [7]. Recently, various tunable resonators have been proposed and demonstrated to achieve tunable resonances using nematic liquid crystals [8], the photocapacitance of semi-insulating GaAs [9] or the thermo-optical effect [10].…”

Comparative Analysis of Split-Ring Resonators for Tunable Negative Permeability Metamaterials Based on Anisotropic Dielectric Substrates

“…Hence, it is possible to achieve the manipulation over the structure via altering the resonance conditions. For example, simulations and experiments performed at microwave frequencies have shown that metamaterials can be controlled by mounting varactors or photocapacitances to their inner structures [12][13][14][15]. In [3], the authors proposed a tunable LHM based on the broadside-coupled SRR (BC-SRR).…”