Ordering Information – Reference Flats & Mirrors

Here is information required to order reference flats and mirrors complete with sample.

Abbreviation Selection
F Flat F
D Diameter (mm) Numerical value
CA Clear Aperture (mm) Numerical value
t Thickness (mm) Numerical value
λ Surface accuracy
(P-V at 633nm)
4 for λ/4
8 for λ/8
10 for λ/10
20 for λ/20
SQ Surface quality
(Scratch / Dig)
60 – 40 for 60/40
40 – 20 for 40/20
20 – 10 for 20/10
10 – 5 for 10/5
Mtl Material P for Pyrex or equivalent
Q for Fused Quartz or equivalent
Z for Zerodur or equivalent
Ct Coating Al for Protected Aluminium
Ag for Protected Silver
Au for Protected Gold
UC for Unocated
Mnt Mount and Mounting M for Mounted on OS mount
UM for Un-Mounted

A flat mirror with the following specifications would read as the Sample Ordering Code below.

Type: Flat
Diameter: 305 mm
Clear Aperture: 290 mm
Thickness: 50 mm
Surface accuracy: λ/10 P-V at 633nm
Surface quality: 60/40
Material: Zerodur or equivalent
Coating: Protected Aluminium
Mounting: Mounted on OS Mount

Sample Ordering Code

F D CA t λ SQ Mtl Ct Mnt
F / 305 / 290 / 50 / 10 / 60-40 / Z / Al / M