Photonic Sourcing

Germanium transmission cuts on at 1.8µm and has useful transmission until 14µm. Knight Optical’s Germanium windows and lenses are used in thermal imaging cameras, where inert and rugged optics are required. Germanium offers high index and low dispersion and is typically used at 3-5µm and 8-12µm bands for passive thermal imaging and hot-spot detection in security and defence applications, night vision systems, and other heat imaging applications such as fire fighting. Because of its high index, germanium is usually AR coated.   Knight Optical can supply Germanium as blanks, windows, spherical and aspheric lenses:

• Diameter: 1 – 450mm
• Thickness: 0.07 – 60mm
• Tolerances: ±0.02mm
• Surface Quality: 10/5 Scratch/Dig
• Flatness: λ/10
• Parallelism: 2”

Applications for Germanium:

• Rugged Thermal Imaging Cameras
• Heat-spot detection in fire fighting
• Laser steering for CO2 laser systems

Rugged Thermal Imaging Cameras:

Germanium is a popular choice for the front optics of thermal imaging cameras, such as lenses and windows. The transmission range of Germanium, from 2 to 14µm, makes it useful for IR imaging systems designed for the 3 - 5 and 8 - 12µm ranges. Germanium's high index means that the use of anti-reflective coatings dramatically increse the transmission offered by the material. Coatings can be optimised for 3-5µm and 8-12µm, as well as for broadband ranges across Germanium's transmission range.

Heat-Spot detection with Thermography in fire fighting:

Germanium is used as the front facing optical components in thermal imaging used in thermography for fire fighting, where smoke and excessive heat make normal imaging methods impractical. Locations of hazards, fires and trapped people can be identified by utilizing the IR radiation emitted. Thermography allows these features to be located in real time, offering a valuable tool in a time-critical application. The addition of Diamond-like coatings (DLC) offer increased ruggedness in applications such as this where durability is essential.

Laser Steering for CO2 Laser Systems:

Solid Germanium Plano-convex, positive meniscus and aspheric lenses with transmission from 1.8 to 23 microns, as well as windows up to 400mm in diameter allow collimation and focus of CO2 laser systems for precision welding. Further enhancement of performance is obtained with Diamond-like coatings in addition to anti-reflective and low absorption coatings.  

Contact our Technical sales team to discuss your specifications and requirements for Germanium optical components.