EMI Shielding Effectiveness and Heater Behavior for Ge IR Windows

In this study, infrared (IR) optic windows having 0.5 mm thickness are produced from n‐type Ge single crystal, which is grown by the Czochralski (CZ) technique. Metallic mesh and antireflective (AR) layer are coated on the Ge windows. Electromagnetic interference (EMI) shielding effectiveness (SE) and heater behavior are determined of the IR windows. Metallic mesh geometry is adjusted zeroth order beam transmittance to be ≈82% combined with a low sheet resistance as ≈1.13 Ω sq⁻¹. Optical transmission (OT) of the Au‐meshed Ge is obtained about 81% by coating the AR layer. SE measurements of the Ge windows having with and without metallic mesh are performed by flanged coaxial SE tester according to the ASTM D4935‐99. The SE value is increased from 2.8 dB (for S1) to 36.3 dB (for S2) owing to the Au mesh. In addition, the heater behavior and IR optical transmission dependent on temperature of the Ge windows are evaluated. The temperature of the Au‐meshed Ge window reaches to around 60 °C end of the 10 s under the 4 V. Finally, decreasing of IR optical transmission and absorbing edge shifting to lower energy of Ge windows are determined as depending on increasing of the temperature.