This is a 12-246 25 mm Dia. Infrared (IR) Neutral Density Filter, with an Optical Density (OD) of 2, specifically designed for the 2-14µm wavelength range. The filter is sourced from the renowned optical component vendor, Edmund Optics, and is available for purchase through their website.
The filter is a Circular type, made of Germanium Burnett material, and features AR coating on both the front and back surfaces, identified as 'edm 12-015'. This coating enhances the filter's performance by reducing reflections and increasing transmission. The filter's geometry includes a diameter of 25 mm and a thickness of 1 mm, and it follows a Thin Lens shape.
The 12-246 filter is a Neutral Density Filter, which means it reduces the intensity of incoming light across the entire spectrum without altering the light's color composition. This makes it an ideal choice for applications where light intensity needs to be controlled without affecting the color balance.
Please note that the filter's availability is subject to change, and interested users are advised to check the vendor's website for the most current status.