Off-axis parabolic mirrors are designed to direct and focus incident collimated light at a specific angle with minimal scatter loss. They are segments of a full paraboloid with a circular cross-sectional aperture and the optical axis is folded 90° and displaced from the mechanical axis, giving unobstructed access. They are available with one of four coatings: UV-enhanced aluminum (250 – 450 nm), protected aluminum (450 nm – 20 µm), protected silver (450 nm – 20 µm), and protected or unprotected gold (800 nm – 20 µm).