Design and analysis high extinction ratio monolithic polarization-integrated super pixel long wavelength infrared detectors

The polarization-integrated infrared detector (PIID) can distinguish the intrinsic property polarization of artificial target and background, and improve the capability of target detection and recognition. In this paper, we use the finite element method (FEM) to build the physical model of long wavelength (LWIR) PIID (8-14um) detector based on InAs/GaSb II superlattices (T2SLs). Our calculation results show thate grating array period, grating line width and thickness can effectively influence the light crosstalk between adjacent pixels, which is the key to the device extinction ratio. In addition, we design micro-structure to PIID, which plays an important role in improving device extinction. As a result, the extinction ratio was improved from 75:1 to 610:1 at the wavelength of 10.9μm. The physical mechanism of suppressing extinction ratio is analyzed in detail.