Abstract

White light interferometry is largerly used for measure glass optical thickness with sub-micrometric accuracy. Usually one of the interferometer arm is moving in order to scan, along the optical axis, the point-surface under test. We show here an alternative set-up, where the reference wavefront is spatially dispersed and no moving part is necessary inside the interferometer. A bidimensional image sensor is used for sample the spatially-dispersed interferogram and the depth information of a transparent glass window is performed in a single shot, i. e. without scanning any system. The interometer is useful for measure optical thickness up to many millimeter without using any moving parts. A prototype for measure up to 1 mm of optical thickness has been built and tested and the results are shown here.

© 2017 Optical Society of America