Metasurface Color Filters Using Aluminum and Lithium Niobate Configurations

Abstract

Two designs of metasurface color filters (MCFs) using aluminum and lithium niobate (LN) configurations are proposed and numerically studied. They are denoted as tunable aluminum metasurface (TAM) and tunable LN metasurface (TLNM), respectively. The configurations of MCFs are composed of suspended metasurfaces above aluminum mirror layers to form a Fabry-Perot (F-P) resonator. The resonances of TAM and TLNM are red-shifted with tuning ranges of 100 nm and 111 nm, respectively, by changing the gap between the bottom mirror layer and top metasurface. Furthermore, the proposed devices exhibit perfect absorption with ultra-narrow bandwidth spanning the whole visible spectral range by composing the corresponding geometrical parameters. To increase the flexibility and applicability of proposed devices, TAM exhibits high sensitivity of 481.5 nm/RIU and TLNM exhibits high figure-of-merit (FOM) of 97.5 when the devices are exposed in surrounding environment with different refraction indexes. The adoption of LN-based metasurface can enhance FWHM and FOM values as 10-fold and 7-fold compared to those of Al-based metasurface, which greatly improves the optical performance and exhibits great potential in sensing applications. These proposed designs provide an effective approach for tunable high-efficiency color filters and sensors by using LN-based metamaterial.

Reconfigurable metamaterials for optoelectronic applications

“…[79] The same research group also demonstrated two designs of high-efficiency reconfigurable color filter based on suspended rectangular Al and elliptical lithium niobate (LiNbO 3 ) metasurfaces on Si substrate coated with an Al mirror layer atop as shown in Figure 4(b). [80] Zhang et al proposed multilayer gratings by using superimposed metamaterial/metal/dielectric thin-films for hyperbolic spatial frequency filtering. This design performs the high extinction ratio of polarization characteristic in the visible light as shown in Figure 4(c) [81] .…”

“…[84] In Figure 4(g), Tuan et al proposed a broadband metamaterial based on Figure 4. Reconfigurable visible metamaterials for (a) absorber, [79] (b) filter, [80] (c and d) polarizer, [81,82] (e) sensor, [83] (f) switch, [84] and (g) resonator [72] applications.…”

Design of Tunable Terahertz Metamaterial Sensor with Single- and Dual-Resonance Characteristic

“…On the basis of Pendry et al, the metamaterial based on SRR was fabricated by Smith et al [12], and they observed the negative refractive index phenomenon. Until now, many derivative structures have demonstrated-such as I-shaped SRR, U-shaped SRR, and 3D-SRR, and complementary structures [13][14][15][16][17][18]-which can be used to span the visible [19,20], infrared [21,22], and THz [23][24][25] spectra ranges. The electromagnetic characteristics of various metamaterials are Fano resonance [26], electromagnetically induced transparency effect [27], and spoof surface plasmons [28,29].…”

Tunable Infrared Metamaterial Emitter for Gas Sensing Application

“…They are widely studied to realize thermal emitters and are perfect absorbers for energy harvesting, medical imaging, and high-sensitivity sensing applications [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. By tailoring the geometrical dimensions, metamaterials can be designed to span broad operating wavelengths, including visible [ 31 , 32 , 33 ], IR [ 34 , 35 , 36 , 37 , 38 , 39 ], terahertz [ 40 , 41 , 42 , 43 , 44 ], and microwave light [ 45 , 46 ]. To provide metamaterials with more flexibility, there are many techniques proposed for tuning mechanisms using MEMS technology [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ]: liquid crystal [ 55 ], photo-excited [ 56 ], phase-change materials [ 57 , 58 ], thermal annealing [ …”