ZnSe (Zinc Selenide) Optical Wedge Prism / Wedged Window
Specifications
Prism / Element Type: Optical Wedge (Wedged Window), Circular
Substrate Material: CVD Zinc Selenide (ZnSe), Laser Grade
Refractive Index: n ≈ 2.4028 @ 10.6 µm; n ≈ 2.58 @ 632.8 nm (for alignment reference)
Typical Diameter: 12.7 mm / 25.4 mm (custom Ø5–50 mm+ available)
Diameter Tolerance: +0.00 / –0.20 mm
Typical Thickness: 3.0 mm / 5.0 mm (center thick side)
Thickness Tolerance: ±0.10 mm
Wedge Angle: 30 arcmin (0.5°) or 3° standard; 0.25°–10° on request
Wedge Angle Tolerance: ±10 arcmin (±3′–±15′ tighter available)
Surface Flatness: λ/4 @ 632.8 nm (over central CA); λ/2 over full aperture
Surface Quality: 40-20 or 60-40 Scratch-Dig (per MIL-PRF-13830B)
Clear Aperture: > 90% of diameter
Transmission Range: 0.6 µm – 16 µm (uncoated); optimal IR use 2–14 µm
Coating Options: Uncoated / BBAR both sides –D coat (1.65–3.0 µm) / –E3 coat (7–12 µm, Ravg <1%) / Partial reflectance on front face
Beam Deviation: δ ≈ (n–1)×α (e.g., ~0.7° deviation @10.6 µm for 0.5° wedge)
Chamfer / Edge: Protective bevel 0.2–0.5 mm × 45°
Density: 5.27 g/cm³ | Knoop Hardness: ~120 kg/mm²
