Double Sided Optical Flats

Double sided optical flats may be used as a reference (test plate) against which the flatness of an unknown surface may be compared or as an optical window. Advanced Optics offers double sided optical flats made of low expansion borosilicate glass, fused quartz, fused silica and Zerodur up to 8" in diameter to meet various demanding applications. Surface flatness of 1/4 and 1/10 wave are available in low expansion borosilicate glass and 1/4, 1/10 and 1/20 wave in fused quartz, fused silica and Zerodur. In addition to our in-stock optical flats, we offer custom fabrication to meet exact customer requirements.

Optical Flat Specifications

Many of Advanced Optics optical flats are manufactured out of synthetic fused silica which provides superior transmission characteristics, a high degree of purity, exceptional environmental durability, and a low coefficient of thermal expansion. Due to these attributes, our double sided optical flats may be used as an optical window.

The accuracy of each optical flat is traceable to the National Institute of Standards and Technology.

Surface Accuracy Double Sided

Surface Accuracy: Double Sided

Diameter

Fused Silica (Thickness)

1/20 wave (0.000001") 25.4 (1") 12.7 (1/2")
1/10 wave (0.000002") 25.4 (1") 12.7 (1/2")
1/20 wave (0.000001") 50.8 (2") 15.9 (5/8")
1/10 wave (0.000002") 50.8 (2") 15.9 (5/8")
1/20 wave (0.000001") 76.2 (3") 15.9 (5/8")
1/10 wave (0.000002") 76.2 (3") 15.9 (5/8")
1/20 wave (0.000001") 101.6 (4") 19.1 (3/4")
1/10 wave (0.000002") 101.6 (4") 19.1 (3/4")
1/20 wave (0.000001") 127 (5") 19.1 (3/4")
1/10 wave (0.000002") 127 (5") 19.1 (3/4")
1/20 wave (0.000001") 152.4 (6") 25.4 (1")
1/10 wave (0.000002") 152.4 (6") 25.4 (1")
1/20 wave (0.000001") 203.2 (8") 33.8 (1.33")
1/10 wave (0.000002") 203.2 (8") 33.8 (1.33")

Fused Silica Technical Data Sheet from Corning IncorporatedFused Silica Technical Data Sheet from Corning Incorporated (pdf)

Advanced Optics offers optical flat resurfacing for double sided optical flats. Optical flats and windows become worn and abraded in use and accuracy is lost. This degradation in performance is due to a decrease in the distinctness of the interference pattern, and to a change in figure caused by scratches. Repolishing the surface of the optical flat back to its original accuracy can be less costly than replacement. Advanced Optics maintains an optical flat refinishing service with fast turn-around time.

Flatness Error of One Fringe 
(1/2 wave)
(top view of optical flat)
Test Piece Perfectly Flat
(top view of optical flat)
top view of optical flat top view of optical flat

Contact Advanced OpticsContact us at (262) 548-1155 or email. Our engineers are waiting to serve you.