Methodology for High Purity Broadband Near-Unity THz Linear Polarization Converter and its Switching Characteristics

Abstract

Terahertz (THz) polarization converter with high purity of linear polarization conversion, broader conversion band and near-unity conversion efficiency is one of the main research interests in the photonic field. Based on a tri-layer structure of Au, parylene-C and Au, a high purity broadband near-unity THz converter is successfully achieved, and the relative bandwidth (RBW) with polarization conversion ratio (PCR) greater than 98% (90%) can reach about 64.782% (73.094%). The ellipticity is close to zero and the polarization azimuth angle is almost equal to ±90 • within the frequency range of 1.818∼2.631 THz. These performances originate mainly from the hybridization of the electric excitations and strong coupling effect among the three resonant modes. Besides, the dependencies of conversion performances on the material's electromagnetic parameters and structural parameters are discussed in detail. By selecting metal material with high conductivity and dielectric material with small real and imaginary permittivities, the conversion performances of the proposed converter can be well improved. Meanwhile, the conversion performances are highly robust when the structural parameters change slightly near the optimized value. Finally, the influences of the incident angle and the polarization angle on the conversion performances are also investigated, and the results show that the proposed converter has the characteristics of wide incident angle and polarization angle dependent switching performance. The simple geometry and the better performances make the proposed linear polarization converter a potential candidate in the area of sub-wavelength scale polarization converters, filters, sensors, switches, and so on.INDEX TERMS High purity, broadband, polarization converter, switching characteristics.

A Dual-band Polarization Insensitive Metamaterial Absorber With a Single Metal Square Patch for Sensing Application

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. These applications are mainly attributed to the unique properties of sub-wavelength metallic structure supporting localized surface plasmonic resonance modes [16][17][18][19][20][21][22][23][24][25][26][27]. Recently, it is shown the inherent losses of metallic structures can enhance absorption and achieve perfect absorption by specific structures [28][29][30][31][32].…”

“…While narrowband absorbers are applied for photodetectors and sensor [9,14]. Unfortunately, most of the metamaterial absorbers reported are single absorption bandwidth that are polarization-sensitive, which significantly obstacle their practical applications [20][21][22][23]. It is necessary to design dual-or multiband metamaterial absorbers with polarization-insensitive.…”

A dual-band polarization insensitive metamaterial absorber with a single metal square patch for sensing application

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. These applications are mainly attributed to the unique properties of sub-wavelength metallic structure supporting localized surface plasmonic resonance modes [16][17][18][19][20][21][22][23][24][25][26][27]. Recently, it is shown the inherent losses of metallic structures can enhance absorption and achieve perfect absorption by speci c structures [28][29][30][31][32].…”

“…While narrowband absorbers are applied for photodetectors and sensor [9,14]. Unfortunately, most of the metamaterial absorbers reported are single absorption bandwidth that are polarization-sensitive, which signi cantly obstacle their practical applications [20][21][22][23]. It is necessary to design dual-or multiband metamaterial absorbers with polarization-insensitive.…”

A Polarization-insensitive Dual-band Plasmonic Metamaterial Absorber for a Sensor Application

“…Recently, plasmonic metamaterials with their unordinary properties have obtained important progress due to their promising applications such as bio-sensor, absorbers, filters and photonic modulators [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Most of these applications greatly benefit from the unique properties of the sub-wavelength metallic structure supporting localized surface plasmonic resonance modes [16][17][18][19][20][21][22][23][24][25][26][27]. For these metamaterials devices, metamaterial absorbers have attracted much attention because of their excellent properties and wide applications [28][29][30][31].Generally, metamaterial absorber can be classified as broadband and narrowband type according to their different application requirements.…”