In this work, we investigated the effect of 2 MeV proton irradiation on the performance of InAs/GaSb type-II superlattice long-wave infrared detectors by combining ground-based irradiation experiments with Stopping and Range of Ions in Matter (SRIM) computer simulations. We found that irradiation with 2 MeV protons significantly increases the dark current density of the detector by more than two orders of magnitude. At the same time, the quantum efficiency decreases by an order of magnitude. Moreover, proton irradiation degrades the device's performance by raising bulk and surface leakage currents. As the mesa size of the device increases, the proportion of surface leakage current in the total dark current drops. When the mesa size is smaller, the detector irradiation damage is greater. In addition, simulations indicate that the amount of damage produced by 2 MeV proton irradiation rises as irradiation fluences increase. The trends of the irradiation damage produced by the SRIM simulation results and the photocurrent measurements after proton irradiation are consistent, whereas the dark current measurements are identical only at small fluences.

No abstract

No abstract

Integrated polarization focal plane detection imaging has the advantages of small size, high system integration, high mechanical stability and real-time polarization imaging in multiple polarization directions. We have developed a simulation model for back-illuminated mid-wave InAs/GaSb Type-II superlattices (T2SLs) infrared focal plane arrays (FPAs) on-chip integrated polarization grating. The polarization grating is an Al-ZnS double-layer subwavelength grating with antireflection coating, which has a better polarization transmission than a single-layer Al grating with the same deep slot. The effect of different grating parameters on the detector is simulated and optimized by the finite-difference timedomain (FDTD) method, and the results obtained are qualitatively interpreted in a physical sense by the Fabry-Perot-like (F-P-like) resonance theory. The optimized grating has a TM polarization transmittance higher than 92% and extinction ratios greater than 32 dB for wavelengths from 3-5 µm, and is suitable for infrared polarization imaging in the 0°-50°f ield-of-view range. The simulation results can provide theoretical basis and guidance for the design of polarization gratings for mid-infrared monolithic integrated polarization InAs/GaSb T2SLs FPAs.