This is the GE-W-63.5-6, a 63.5 mm diameter Germanium Flat Window with a thickness of 6mm, uncoated and sourced from Alkor Technologies. The item is a Window type of optical element, specifically a Flat Window, with a base shape of Circular.
The geometry of this component is defined by its diameter and thickness. The diameter, which is 63.5 mm, is the overall size of the window, while the thickness, 6mm, refers to the depth of the germanium material used. The uncoated nature of this window means it does not have any additional layers applied to its surface, which can affect its optical properties.
The material of this window is germanium burnett. Germanium is a common material in optical components due to its excellent transmission properties in the infrared region of the spectrum. This particular window is designed for use at a wavelength of 10600 nm.
The window's shape is that of a Thin Lens, which suggests that it may have some slight focusing properties, although this is not its primary function. The lens shape could potentially be used to correct for minor aberrations in an optical system, although this would depend on the specific application.
For more information about this product, including pricing and availability, please refer to the vendor's website at http://www.alkor.net/germanium_windows_catalog.html.