عينة شاهدة، انعكاس، 1.400-1.899

The 60-40 scratch dig on the polished face is exactly what I needed for our coating runs, and the surface came out clean with no sleeks under the loupe. Flatness held under 1 wave at 633nm too, which I checked on our interferometer.

Ordered the 1.400-1.899 range sample to check our reflection setup before a big run, and the flatness held up nicely at 633nm. Back side being ground doesn't bother me since I only needed the polished face. Held it against our reference and the readings matched.

The polished surface is remarkably clean for a witness sample—no visible scratches under my loupe, and the flatness held up perfectly on the interferometer. Ground back side makes it easy to handle without worrying about damaging the optical face.