Important information for customers from the EU

Please note that the Principality of Liechtenstein is not a member of the EU. For this reason, the following points must be observed:

TVA – Value Added Tax

Our prices are exclusive of VAT and will be shipped as such. I.e. concretely, you have to pay the value added tax (TVA) when importing into your country (an EU country). You can reclaim these taxes from your state.

Customs clearance – EORI number required

All companies need a so-called EORI number (Economic Operator’s Registration and Identification) to import from non-EU countries. This number is used for your identification as well as for the automated customs clearance, i.e. for the import into your country (an EU country).

The respective national issuing office of the EORI number can be found on the website of the European Union. In Germany and Austria, the EORI number is assigned by customs.

Silicon and Germanium

We supply high quality silicon and germanium crystals, produced by the Czochralski process.

The properties such as electrical resistance, IR transmission, crystal orientation and residual stress of the crystals can be adjusted according to customer requirements.

Our delivery program includes


  • Customised sizes
  • Ø up to 457.2 mm
  • Thickness up to 381 mm

CNC machined parts

  • Complex geometries
  • Sizes up to 444.5 mm
  • Tolerances smaller than 0.015 mm
  • Surface roughness up to 16 µm

Curved surfaces

  • Sizes up to Ø 368.3 mm
  • Sag tolerance: ±1 µm
  • Aspheres: Near net curve fit available

Polished substrates

  • Flat larger Ø 355.6 mm, spherical larger Ø 203.2 mm possible
  • S/D: better than 20/10
  • Surface roughness: flat less than 15 Å, spherical on request
  • Flatness: flat better than λ/10, spherical better than λ/4


  • Infrared windows and lenses
  • Laser mirrors
  • Wafers for semiconductors
  • Coating materials

Transmission curve Silicon

Transmission curve Germanium

You are interested in Silicon and Germanium?

Contact us!

5 reasons for Filtrop: