Compare Model Drawings, CAD & Specs Diameter Antireflection Coating Thickness Parallelism Availability Price
$213
In Stock
25.4 mm Uncoated 2.0 mm < 3 arc minute
In Stock
$329
In Stock
25.0 mm 3-12 µm 3.0 mm < 1 arc minute
In Stock
$777
In Stock
50.0 mm 3-12 µm 3.0 mm < 1 arc minute
In Stock
$1,299
74.9 mm 3-12 µm 5.0 mm < 1 arc minute

Specifications

  • Material
    Optical Grade Germanium
  • Surface Flatness
    λ/20 @ 10.6 µm
  • Surface Quality
    40-20 scratch-dig
  • Cleaning
  • Clear Aperture
    10GE20: central 85% of diameter
    GEW: central 90% of diameter
  • Diameter Tolerance
    10GE20: ±0.2 mm
    GEW: +0.0/-0.1 mm
  • Thermal Expansion Coefficient
    6.1 x 10-6 K-1 @ 298 K
  • Thermal Limit
    59 W m-1 K-1 @ 293 K

Features

3 to 12 µm Broadband Coating

The AR.20 broadband anti-reflection coating offered with our Germanium parallel windows is effective from 3 µm to 12 µm.

Germanium Optical Properties

Germanium Optical Windows have good transmittance from 2 to 16 µm uncoated, and very low peak absorption, making the material an excellent candidate for use in C02 laser cavities. Germanium also has high opacity across the entire visible spectrum, making the windows ideal for applications where transmission of only IR wavelengths is desired.