Optical Materials | Sapphire, Quartz, ZnSe & ZnS Selection Hub
This material hub provides side-by-side comparison of optical substrates, with clear differentiation between crystal quartz, fused silica and synthetic fused silica, plus infrared material performance tables. Sapphire (single-crystal α-Al₂O₃) is one of the most durable optical substrates, widely used for high-temperature windows, protective cover glass and harsh-environment EO/IR optics. It delivers broadband transmission from deep UV to mid-infrared, extreme scratch resistance and outstanding thermal shock resistance. Felix Glass supplies C-axis and A-axis oriented sapphire blanks, polished windows and custom machined components with AR coatings for UV, visible and MWIR wavebands. 1. Best for: high-temperature observation windows, rugged display cover glass, IR protective domes, plasma viewports.
2. Limitation: Brittle under heavy impact; not suitable for ultra-long wave infrared beyond 5.5 μm.
3. Coating match: Broadband AR coatings greatly improve surface transmission for imaging and laser systems. Many engineers confuse three common SiO₂-based optical materials: natural crystal quartz, conventional fused silica and high-purity synthetic fused silica. The key differences lie in UV transmission purity, water (OH) absorption and thermal stability, which directly determine suitability for deep-UV lasers, spectroscopy and high-power laser optics. • Deep-UV (193/248 nm excimer laser): Choose low-OH synthetic fused silica (JGS1 grade).
• General UV-Vis (≥260 nm): Standard fused silica is cost-effective.
• Near-infrared (2–3.5 μm): Select low-OH fused silica to avoid the 2.7 μm water absorption peak.
• Polarized optical paths: Only use single-crystal quartz and control crystal axis orientation to manage birefringence. CVD-grown ZnSe and ZnS are the two dominant mid-infrared substrate materials for CO₂ laser optics and thermal imaging windows. The choice hinges on laser absorption, mechanical hardness, multi-band transmission and cost. ZnSe is the gold standard for 10.6 μm CO₂ laser systems; ZnS offers higher hardness and better environmental durability for rugged IR imaging domes. • High-power 10.6 μm CO₂ laser cavities & output windows: Pick CVD ZnSe with low-absorption AR coating.
• Rugged thermal imaging domes, outdoor IR cameras: Choose standard CVD ZnS for higher mechanical strength.
• Multi-band systems (visible + 3–5 μm MWIR): Select multi-spectral clear ZnS for broad-spectrum transmission.
• Cost note: ZnSe and standard ZnS have similar raw material costs; the main price difference comes from polishing and coating specifications. Related categories: Sapphire Optics, Quartz Glass, ZnSe Optics We supply polished blanks, finished windows and coated components in sapphire, quartz, fused silica, ZnSe and ZnS, with full optical testing and material grade certification.Optical Materials
Technical Articles In This Category
Sapphire Optical Material Properties
Overview
Core Optical Performance
Mechanical & Thermal Properties
Typical Application Boundaries
Crystal Quartz vs Fused Silica vs Synthetic Fused Silica
Overview
1. Material Structure & Purity Difference
2. Key Optical & Thermal Comparison
Quick Material Selection Rules
ZnSe & ZnS Infrared Substrate Selection
Overview
1. Optical Transmission Performance
2. Mechanical & Thermal Trade-offs
3. Final Selection Guide
Browse More Topics
Custom Optical Substrate Manufacturing
