EMI shielding sapphire optical windows with high transmittance via aerosol jet printed silver mesh and antireflection coatings
OPTICAL MATERIALS, cilt.178, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 178
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.optmat.2026.118275
- Dergi Adı: OPTICAL MATERIALS
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, Chimica, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Gazi Üniversitesi Adresli: Evet
Özet
Transparent electromagnetic interference (EMI) shielding is a critical requirement for advanced optoelectronic and defense systems operating across the visible to mid-infrared spectral ranges. In this study, high-performance EMI-shielding sapphire optical windows were designed, fabricated, and characterized using Kyropoulos-grown optical-grade single-crystal sapphire. Precision slicing followed by multistage lapping and polishing yielded optical windows with sub-nanometer surface roughness (R-a = 0.52 nm). Broadband optical transmittance was enhanced through optimized SiO2 antireflection (AR) coatings deposited on both surfaces of the sapphire window. A periodic silver (Ag) metal mesh architecture with a nominal linewidth of 25-30 mu m and a pitch of 295 mu m was integrated by aerosol jet printing (AJP), resulting in a sheet resistance of 2.06 Omega sq(-1) while maintaining optical transmittance above 70% in the 1.3-4.5 mu m infrared band and above 85% in the visible-near-infrared region. The fabricated optical windows exhibited an EMI shielding effectiveness of 10-27 dB over the 1-18 GHz frequency range. Temperature-dependent optical measurements performed from 25 degrees C to 250 degrees C confirmed excellent thermal stability with negligible degradation in optical transmittance. The demonstrated combination of high optical transparency, low sheet resistance, effective EMI shielding, and thermal robustness establishes sapphire-based metal mesh optical windows as a promising platform for next-generation airborne, naval, and spaceborne electro-optical systems.