A multilayer film based on thin-film interference and impedance matching for dual-laser and infrared stealth as well as thermal management

Abstract

Multispectral compatible stealth encounters higher challenges and requirements with the combined application of multiple detection technologies. This paper proposes a multilayer film based on thin-film interference and impedance matching to achieve 1.06 µm and 1.54 µm dual-laser stealth and mid-wavelength infrared (MWIR, 3–5 µm) and long-wavelength infrared (LWIR, 8–14 µm) stealth, as well as thermal management by the non-atmospheric window (5–8 µm). The multilayer film consists of Al2O3, Fe3O4, ZnS, Ge and Ag layer (Al2O3/ZnS/Ge/Ag/Fe3O4/Ag) and the optical performance of multilayer film is calculated using the finite-difference time-domain (FDTD) method. The numerical results indicated that the spectral emissivity of the multilayer film is lower than 27 % in the MWIR and 14 % in the LWIR and the spectral absorptances are both over 98 % at the laser wavelength 1.06 µm and 1.54 µm, respectively, as well as in the non-atmospheric window. Moreover, the optical performance of the multilayer film could be influenced with incident angle whether it is TM or TE wave but independent of the polarization angle. This work provides theoretical guidance for design and optimization of multilayer film that processes the compatibility of infrared stealth in the MWIR and LWIR and dual-laser stealth with thermal management in the non-atmospheric windows.