Real-time and high-transmitted middle-infrared optical imaging system based on pixel-wise metasurface micropolarization array


 Real-time polarization medium-wave infrared (MIR) optical imaging systems enable the acquisition of infrared and polarization information of a target. At present, real-time polarization middle-infrared devices mainly face the following problems: poor real-time performance, low transmission, and high requirements for fabrication and integration. Herein, we need to improve the performance of the real-time polarization imaging system in the MIR waveband and solve the above-mentioned defects. Therefore, we propose an MIR polarization imaging system for achieving real-time polarization-modulated imaging with high transmission as well as improved performance based on a pixel-wise metasurface micro-polarization array (PMMPA). The PMMPA element comprises several linear polarization (LP) filters with different polarization angles. The optimization results demonstrate that the transmittance of the LP filters is up to 77% at a wavelength of 4.0 μm and an extinction ratio of 88 dB. In addition, a near-diffraction-limited real-time MIR imaging optical system is designed with a field of view (FOV) of 5ºand an F-number of 2. The simulation results show that an MIR polarization imaging system with excellent real-time performance and high transmission is achieved by using an optimized PMMPA element. Therefore, the method is compatible with the available optical system design technologies and provides a way to realize real-time polarization imaging in mid-infrared wavebands.