Anti-Reflection Coated Germanium Windows

We supply a wide range of anti-reflection coated germanium windows in a variety of shapes and sizes, both off the shelf and custom-made for your exact requirements.
Germanium (Ge) is a hard, high-density, IR transmitting material that blocks UV (ultraviolet) and VIS (visible) wavelengths but allows IR from 2µm. Germanium has the highest RI (refractive index) of commonly available IR-transmitters and has low optical dispersion.

Germanium transmits over 45% between 2-14?m up to 45°C, but transmission degrades slowly at 100°C then more rapidly above 200°C. Exposure to higher temperatures can lead to catastrophic failure in the material so Germanium is not suited for use in these conditions. Where weight is an issue, its relatively high density (5.327gm/cc) should be considered .
Typical applications for Germanium include thermal imaging where the material can be used as a front optic while its index of refraction makes Germanium useful for wide-angle lenses and microscopes. Additionally, Germanium components can be used for FLIR (Forward Looking Infrared) and FTIR (Fourier Transformed Infrared) spectroscopy systems, alongside other analytical instruments.
Our stock Germanium windows are available for worldwide shipping today .Please contact our sales team for advice and to help you select the best windows for your application.
Our stock windows include 50mm x 3mm AR DLC coated Germanium Windows, 75mm x 3mm AR DLC coated Germanium Windows and 100mm x 6mm AR DLC coated Germanium Windows. See below for full specifications and details on how to order.
Specific coatings applied to stock items are listed below.
Custom coatings for Germanium windows available on request

MATERIAL

GERMANIUM OPTICAL GRADE MONO CRYSTALLINE

DIAMETER TOLERANCE

+ 0.00 / - 0.1mm

THICKNESS TOLERANCE

± 0.1mm

EDGES

Fine ground

SURFACE QUALITY

60/40

FLATNESS

≤ 5 fringes

PARALLELISM

≤ 3 arc mins

COATINGS

See below

CUSTOM MADE SIZES

DIMENSIONS

DIAMETER 5mm TO 300mm / SQUARES, RECTANGLES OR CUSTOM SHAPES ON REQUEST

THICKNESS

0.5mm TO 20mm