Self-calibrating lateral scanning white-light interferometer.

Lateral scanning white-light interferometry represents an attractive alternative to the standard white-light interferometry. Its main advantage over the latter procedure consists in the ability to scan large samples continuously, without the need of a cumbersome stitching procedure. Presently, the main drawback in the path of large-scale industrial acceptance of this method is the need for careful calibration of the tilt angle prior to each measurement. A novel self-calibration approach is presented. Using the data acquired during the normal scanning process, the need of an initial tilt angle calibration is eliminated and on-the-fly system adjustments for the best signal-to-noise ratio can be performed without an increase in the measurement time dictated by recalibration.