KCl (Potassium chloride) optical window for use in FTIR spectroscopy.

• Circular shape
• Large transmission range of 210 nm to 20 μm
• High transmission and high damage threshold
• Can be used up to 400 °C in a dry environment
• Low refractive index

Commonly used for FTIR spectroscopy and CO₂ laser applications.

Surface quality: 60/40 scratch dig
Tolerance: Diameter - ±0.25 mm; Thickness - ±0.25 mm
Aperture: 90% (clear aperture)

Melting point: 776 °C
Parallelism: <3 arc min
Density: 1.989 g/cm³

Young's Modulus: 29.67 (Gpa)
Knoop Hardness: 780 kg/mm²
Coefficient of Thermal Expansion: 36×10⁻⁶/°C