Thorlabs has a wide selection of spherical concave mirrors with metallic or dielectric coatings that together span the 250 nm - 20 µm spectral range, with focal lengths from 9.5 mm to 1000 mm. Our mirrors with dielectric coatings offer >99% average reflectance in the 350 - 400 nm, 400 - 750 nm, 750 - 1100 nm, or 1280 - 1600 nm spectral ranges. Back side polished mirror options are also available for the dielectric coating ranges of 400 - 750 nm and 750 - 1100 nm. Our mirrors with metallic coatings are offered in UV enhanced aluminum (250 - 450 nm), protected aluminum (450 nm - 2 µm), protected silver (450 nm - 2 µm), protected gold (800 nm - 20 µm), and mid-infrared enhanced gold for Herriott cell mirrors (2 - 20 µm). We also offer crystal-coated concave mirrors with extremely high reflectance at 1064 nm or 1550 nm with 1 m radii of curvature.