Polarization-sensitive broadband bidirectional absorber in the optical communication band

Abstract

Here, we propose a polarization-sensitive broadband bidirectional plasmonic absorber in the optical communication band. The proposed structure can achieve an excellent absorption performance (>90%) under the TE wave illumination at the wavelength range from 1370 nm to 1630 nm within an incident angle up to 45°. The analysis of the electromagnetic field distribution reveals that the coupling of propagating surface plasmons resonance and local surface plasmon resonance dominates the perfect absorption performance. The symmetry of the structure determines that the device has the characteristics of bidirectional absorption. In addition, the effect of interlayer alignment accuracy on absorption performance is discussed, and the result indicates that low alignment accuracy is allowed. The bidirectional broadband plasmonic absorber shows a promising prospect in electromagnetic wave shielding, optical sensors, photodetectors, and communication.