Active modulation of polarization-sensitive infrared metamaterial

We present three designs of tunable and polarization-sensitive infrared (IR) metamaterials (PSIMs). They are composed of serpentine-shaped Au nanostructures and denoted as PSIM-1, PSIM-2, and PSIM-3, respectively. By changing the lengths of PSIMs, the tuning ranges of resonant bandwidths/ frequencies could be modified as 2.39μm/780 nm (PSIM-1), 1.97μm/800 nm (PSIM-2), and 2.20μm/860 nm (PSIM-3). Furthermore, they exhibit the switching characteristics of passband and stopband in the wavelength range of 4μm to 9μm by changing the PSIMs lengths at TE and TM modes. The electromagnetic responses show tunable free spectra ranges (FSRs) and single-/dual-band switching characteristics by changing the gaps between the serpentine-shaped Au nanostructures. To increase the flexibility and applicability of PSIMs, the devices are exposed on surrounding environment with different refraction index. The tuning ranges of resonant frequencies are 1.00μm, 1.20μm, and 0.80μm for PSIM-1, PSIM-2, and PSIM-3, respectively. Such multifunctional PSIMs create the possibility for the realization of high-efficiency, polarization switching, single-/dual-band switching, and tunable optoelectronics applications in the IR wavelength range.