12吋參考平面 – 反射率90%，λ/15，PVr

I was a bit worried about matching the lambda/15 spec to my interferometer setup, but the surface quality is exactly what I needed for calibration. The 12-inch diameter gives plenty of room to work with, and the flat performed flawlessly right out of the box.

The 90% reflectivity rating is spot on—our fringe contrast improved dramatically over the old flat. Setup took less than ten minutes, and the lambda/15 surface quality has made sub-nanometer measurements repeatable.

Interferogram quality jumped noticeably once I swapped in this 12-inch flat—the lambda/15 PVr spec holds up in practice, and the 90% reflectivity gave me clean fringes without cranking the laser power. Setup took a bit of fiddling to get the mount alignment right, but the surface itself is dead flat