The present invention adopts a particle dispersed silicon material, comprising silicon carbide as dispersion particles, as a mirror substrate, subjects the mirror substrate to mirror finish polishing to form a mirror body, forms a reflecting film on the mirror body to form a mirror, and uses the mirror to form a large aperture optical system.
A method for producing a mirror (10) from a titanium-based material by using the technique of ultraprecision machining. The mirror produced using this method has both a shape accuracy and a surface roughness in the submicrometer region. The mirror (10) is made from a titanium-based material having a shape accuracy and a surface roughness in the submicrometer region, whose basic shape (11) has a has a reflecting surface (12) having a surface roughness of less than 60 nm, and in particular of less than 30 nm.