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Germanium(Ge) Plano concave Lenses are made from Germanium material. They present a concave surface and a plano surface. They have a negative focal length and are used for image reductinon or to spread light. These lenses diverge collimated incident light and form virtual images which are seen through the lens. They are often used to expand light or to increase focal lengths in existing systems.

Specifications:
Material:-----------------------------------------------------------Germanium
Diameter Tolerance:----------------------------------------------+0.0/-0.15mm
Focal Length Tolerance (mm):----------------------------------+/-2%
Centration:---------------------------------------------------------<3 arc minutes
Clear Aperture:---------------------------------------------------->85%
Surface Figure:-----------------------------------------------------<λ/4@633nm
Surface Quality:-----------------------------------------------------60/40
Protected Bevel:---------------------------------------------------<0.25mmx45deg
Coating:--------------------------------------------------------------uncoated