Single-crystal sapphire (Al2O3) optical windows offering unmatched hardness (Mohs 9) and exceptional transmission from 180nm to 4.5um. Ideal for harsh environments, high-pressure viewports, and applications requiring extreme scratch resistance and chemical inertness.
| Material | Single-crystal Sapphire (Al2O3) |
| Transmission Range | 180 - 4,500 nm |
| Hardness | Mohs 9 (second only to diamond) |
| Refractive Index | no = 1.768, ne = 1.760 @ 587nm |
| Diameter Range | 3mm - 150mm |
| Thickness Range | 0.5mm - 25mm |
| Surface Quality | 20-10 / 40-20 (MIL-PRF-13830B) |
| Surface Flatness | lambda/4 @ 632.8nm |
| Thermal Stability | Stable to 2000 degrees C in air |
| CTE | 5.0 x 10^-6/K (perpendicular to c-axis) |
Parameter Reference Guide
Typical Standard capability — available as shown
Available Alternative options exist — request quotation
Custom Per your drawing — quote after review
Subject to Review Depends on project specifics
Select the optimal optical material based on your wavelength, power, thermal environment and mechanical requirements.
Coatings are engineered around your specific wavelength and operating conditions.
We optimize specifications to match your system requirements — not over-specify. Tighter tolerances increase cost without always improving system performance. Typical manufacturing capabilities:
Every component undergoes 100% inspection before shipment with full documentation including interferometer reports, spectral curves, surface quality images and dimensional data.
Birefringence: Sapphire is birefringent (delta-n = 0.008). For polarized light systems, this can cause unwanted polarization rotation. Account for crystal axis orientation in your design. For unpolarized applications, birefringence is not a concern.
Machining difficulty: Sapphire's extreme hardness makes it more expensive to machine than BK7 or fused silica. Complex geometries (thin edges, small features) significantly increase cost. Keep designs as simple as possible.
Thermal shock: Despite high temperature capability, sapphire can crack under rapid temperature changes due to thermal stress. Specify gradual temperature transitions in your system design.
Upload your drawing or describe your specification. Our engineering team will review and respond within 1 business day.
Sapphire offers unmatched hardness but at a premium. Confirm if the investment is justified.
| Your Need | This Material? | Note |
|---|---|---|
| Abrasive environment | Yes ✓ | Sapphire Mohs 9 is ideal |
| Cleanroom / controlled | No | Fused silica is sufficient at lower cost |
| Your Need | This Material? | Note |
|---|---|---|
| Visible-NIR (200-4500nm) | Yes ✓ | Sapphire has excellent clarity |
| Mid-IR beyond 4.5um | No | Use ZnSe or Ge |
| Your Need | This Material? | Note |
|---|---|---|
| High-pressure viewport | Yes ✓ | Sapphire strength is unmatched |
| Standard conditions | No | Fused silica or BK7 are more economical |
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Specification Parameters
Typical Specifications shown on this page are standard capabilities. Available Options include alternative materials and coatings. Custom Specifications are available per your drawing. Requirements beyond standard capability are marked Subject to Engineering Review.
Upload your drawing or specifications. Our engineering team will review and respond within 1 business day.
When requesting a quote for this product, please specify the following parameters to help our engineering team provide an accurate quotation:
Not sure about specifications? Upload your drawing and our team will assist with engineering review.