Numerical Investigation of an AlN-Based Resonant Detector with a Plasmon Aperture Absorber for Dual-Band IR Sensing

Abstract

An aluminum nitride (AlN) piezoelectric resonant infrared (IR) detector based on a Lame-wave resonator (LWR) and plasmon apertures was designed for dual-band sensing, and was investigated by using the finite element method (FEM) and finite difference time domain (FDTD) simulations. A plasmon structure with the apertures was designed on the surface of the detector in order to maintain electrical performance and to obtain ultrahigh dual-band IR absorption. The electrical performance of the LWR with the plasmon apertures was comparable to that of the LWR with floating electrodes, which was found to be superior to that of the LWRs with plasmon particles or open electrodes. Both of the rectangle aperture and cross-shaped aperture absorbers can achieve ultrahigh dual-band absorptions of up to 97%, and the cross-shaped aperture absorber is insensitive to the polarization angle. Moreover, a detailed optimization analysis for the thermal properties of the detector was conducted to obtain favorable responsivity and response speed. The calculated results demonstrate that the proposed resonant detector has great potential applications in IR detection.