Sapphire Windows

Single Crystal Sapphire Optical Windows

Single crystal sapphire is the second hardest natural material after diamond (Mohs hardness 9), featuring extreme mechanical strength, broad transmission (UV to mid-infrared: 200nm–5500nm), excellent thermal stability, and chemical resistance. Widely used as optical protection windows in harsh environments.

Specifications

ParameterValue
MaterialSingle Crystal Sapphire (Al₂O₃)
Transmission Range200nm–5500nm
Refractive Index (n)no=1.755, ne=1.747 @ 1064nm
Mohs Hardness9 (second only to diamond)
CTE5.3×10⁻⁶/°C (a-axis)
Melting Point2053°C
Diameter RangeØ1mm–Ø300mm
Surface Quality40-20 / 20-10 available
OrientationC-plane / A-plane / R-plane etc.

Coating Services

  • AR Single-wavelength — R < 0.5% at specified wavelength (UV to mid-IR range)
  • AR Broadband — For wide spectral range applications; specify wavelength range
  • Note: sapphire's high refractive index (n≈1.76) means ~8% Fresnel loss per surface uncoated; AR coating strongly recommended for precision applications
  • DLC (Diamond-Like Carbon) coating available on request for added abrasion resistance in extreme environments

Typical Applications

High-Temp / High-Pressure WindowsMilitary & Aerospace WindowsMedical EndoscopesDeep-Sea EquipmentHigh-Power Laser Systems

Need a Custom Quote?

Submit your specifications and we will respond within 24 hours

Request a Quote