-   Material: N-BK7
-   Dimensional tolerance:

        - Dimension:
                - 0 to 50mm : +0  -0.1mm
                - 60 to 120mm : +0  -0.2mm
                - 150 to 250mm : +0  -0.3mm
        - Thickness: ± 0.2mm

-   Surface figure: λ/10 (550nm)

On request: other dimensions and radius of curvature.

Coating (incidence 0°):

-   Concave face:

        - Dielectric:

                - R max > 99.5%, specific wavelength.
                - R max>98%, bandwidth.
                - R = 10% - T = 90% à R = 99% - T = 1%

        - Dichroic:

                - Short wave pass: R>99%, T>95% 

-   Plano face:

        - Anti-reflection R< 0.2%