43-835 25 mm Dia. N-BK7 Concave-Convex Spherical Mirror; EFL=25mm Protected Gold 700-10000nm

This is a 25 mm diameter concave mirror from Edmund Optics, designed with a protected gold coating suitable for wavelengths ranging from 700 to 10000nm. The mirror's geometry is spherical, with both radii of curvature (r1 and r2) measuring -50mm, indicating a concave-convex design. This means that the mirror's center is thicker than its edges, and it has both a concave and a convex surface.

The effective focal length (EFL) of this mirror is 25mm, which is also its diameter. This EFL value suggests that the mirror will focus light to a point approximately 25mm from the mirror's surface. The mirror's thickness at the edge is 3mm, providing structural rigidity while minimizing unnecessary weight.

The mirror is made of N-BK7 glass, a popular choice in optical systems due to its excellent optical properties and wide transparency range. This particular mirror is coated with a protected gold coating (edm prgold 700-10000), which is highly reflective across the infrared spectrum, making it ideal for applications such as thermal imaging, heat seeking, and other infrared-based technologies.