X-Ray Optics Metrology Laboratory

WYKO-6000 Figure Interferometer

The WYKO 6000 figure interferometer measures the deviation of height of a surface from a reference surface. It uses digital phase shifting interferometry. The figure error of optical surfaces up to 150 mm in diameter at normal incidence, or larger optics at grazing incidence angle, can be measured with this instrument.

WYKO-6000 Figure Interferometer
Photograph of the WYKO-6000 station.

The instrument sits on a 3-meter-long and 2-meter-wide optical table. To avoid perturbation from the airflow, the cleanroom airflow system is turned off during the measurements.

With special care, measurements can be performed with an accuracy of lambda/30.

The current setup enables measurement of radii of curvature up to 4 meters.