Flatness interferometer and how it works

Indars Flatness Interferometer

For noncontact flatness measurements, the Indars Flatness Measurement Interferometer is an ideal instrument for thin, transparent wafers, windows and substrates.

The schematic is the top view of the flatness interferometer apparatus with vertical positioning of a thin transparent wafer (1) and precision optical flat (2). The parabolic metallic reflector (3) creates a beam of monochromatic light from a sodium light source (4). The beam has a uniform distribution of light intensity in the plane of matte glass (5), providing the dispersion of wave vectors of waves within a wide solid angle. The interferometer pattern can be observed visually (7) or taken by camera. The inclined background screen (6), having a diffusive surface, is placed between the light source and the thin transparent wafer.


Flatness Measurement Interferometer Schematic

Flatness Measurement Interferometer Schematic



Flatness Measurement Interferometer

Flatness Measurement Interferometer


For additional information on the Patented Indars Flatness Interferometer see:

Please call or e-mail for further details.






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