Zygo Mesa Interferometer
Flatness measurements can be made with the Zygo Mesa interferometer system. It is used to provide feedback during the lapping and polishing processes to ensure that the required shape and slope is being obtained.
The system has been designed to be quick and easy to use giving graphical representations in 2D and 3D as well as numerical data. It is mainly used as an inprocess metrology tool.
The Mesa uses geometrically desensitised interferometry to measure reflective surfaces with the highest level of accuracy and repeatability. The result is an accurate map of the shape and topography of the surface. This is displayed as high resolution graphics that can be rotated, sliced cross sections, numerical data and statistical plots.
The system can measure objects up to 150mm in diameter. The measurement accuracy is λ/100 and the repeatability is λ/2000. The system uses a laser operating at 633nm.
An example of the Zygo interferometer in use can be seen here where it is used to measure the curvature of a sagittal crystal during the process of bending.