Knight Optical can provide germanium windows as both stock and custom options. Germanium is a relatively hard crystalline material which transmits from 1.8µm to 23µm, which encompasses the MWIR and LWIR thermal wavebands. It is an excellent material for thermal imaging applications, as well as low powered CO2 lasers, FTIR spectroscopy, and pyrometers. 

Knight Optical offers stock germanium windows in diameters of 10mm to 100mm, with coated and uncoated options. Our coatings include AR/DLC coatings for the LWIR waveband, or AR/AR coatings covering MWIR to LWIR wavelengths (3-12µm). 

Custom germanium windows can be manufactured to dimensions of 300mm or more with coatings optimised to specific infrared wavelengths. Coatings include antireflective (AR) and diamond-like carbon (DLC) coatings which are ideal if the applied surface is exposed as it enhances the surfaces durability. 

All germanium windows are tested in our metrology and QA departments prior to shipment to ensure conformity to customer specifications.