Tunable Dual‐Split‐Disk Resonator with Electromagnetically Induced Transparency Characteristic
Daoye Zheng, Yu‐Sheng Lin
Abstract
Abstract A tunable dual‐split‐disk resonator (TDSDR) composed of top and bottom Au split‐disk resonators (SDRs) in the terahertz (THz) wave is presented. TDSDR exhibits electromagnetically induced transparency (EIT) characteristic by changing the rotation angle of top SDR (θ) and distance between top and bottom SDRs ( h ). The bright and dark modes are defined by the resonances with θ = 90° and 0°, respectively. The resonances could also be controlled by changing h values. It can generate a tunable sharp resonance by moving the top SDR to change h value. Furthermore, the amplitude of EIT resonance could be tuned and switched on/off state, i.e., bright and dark modes by rotating top SDR with specific h value. When h value is 1 µm, the free spectra range (FSR) could be tuned 0.24 THz and EIT characteristic is not clear. By continuously changing h value to 3 µm, EIT characteristic could be tuned with a modulation depth of 75.58%. The average quality factor ( Q ‐factor) of resonances is 11.54 and average figure of merit (FOM) is 7.06. When h value is enlarged to 5 µm, EIT characteristic could be tuned with a modulation depth of 62.73%, while the average Q ‐factor is 14.50 and average FOM is 9.35.