87-688 25 mm Dia. N-BK7 Plano-Convex Spherical Mirror; EFL=12.5mm Protected Gold 700-2000nm

This 87-688 optical mirror, sourced from Edmund Optics, is a 25 mm diameter plano-convex spherical mirror with a focal length (EFL) of 12.5mm. The mirror is made from N-BK7 Schott glass, a popular choice for its high refractive index and low dispersion, making it ideal for a wide range of optical applications.

The mirror's geometry includes a thickness of 1.65mm at the edge, gradually increasing to 5mm at the center. This design ensures structural integrity while minimizing unnecessary weight. The spherical shape of the mirror, with a radius (R1) of 25mm, allows for a wide range of focusing capabilities.

The mirror's front surface is coated with a protected gold coating, designed to enhance reflectivity within the 700-2000nm wavelength range. This coating not only improves the mirror's performance in the specified wavelength range but also provides excellent durability and resistance to environmental factors, ensuring longevity and reliability.

The mirror's 'protected gold' coating is a type of dielectric coating that provides high reflectivity and excellent environmental stability. The 'protected' aspect of the coating refers to an additional layer that shields the gold from oxidation and other forms of environmental degradation, further enhancing the mirror's lifespan and performance.