After metal or dielectric high reflection coated on the concave substrates, it's a concave mirror. Concave mirror can be focus the light beam or imaging as a lens. The focal length of concave mirror is half of the curvature radius.
It can be widely used in optical equipment.

Specifications:

Material: BK7, UV fused silica, or other optical materials
Diameter Tolerance: +0.0, -0.2mm
Curvature radius tolerance: ±2%
Centration: 3 arc minutes
Clear Aperture: >80%
Surface Irregularity: l/4@632.8nm
Surface Quality: 60-40 scratch and dig
Protective Bevel

Concave surface mirror coated
1. Metal (Aluminium, silver or gold) coated
2.Multi layer dielectric high reflection coated for defined wavelength.

Normal size dia.25.4mm. Other dimension or square shape are available upon request.