46-238 20 mm Dia. N-BK7 λ/4 Concave Spherical Mirror; EFL=40mm Protected Aluminum 400-2000nm

This 46-238 model is a 20 mm diameter concave spherical mirror, featuring a focal length of 40mm and sourced from the renowned optical vendor, Edmund Optics. The mirror's base shape is circular, and it boasts a protective aluminum coating suitable for a wide range of wavelengths, from 400nm to 2000nm.

The mirror's geometry is meticulously crafted, with a thickness of 3.63mm at the edge and 3mm at the center. The concave spherical shape, defined by a radius (r1) of -80, ensures optimal light reflection and focusing. The mirror's effective focal length (EFL) of 40mm further enhances its focusing capabilities.

The mirror is made from N-BK7, a high-quality borosilicate glass known for its excellent optical properties, including low autofluorescence and a wide transmission range. This material is identified in the item data as "n-bk7 schott," indicating its Schott glass origin.

The mirror's front surface is coated with a specialized coating, identified as "edm protal452008000." This coating provides protection, enhances the mirror's durability, and contributes to its wide range of usable wavelengths.