Determination of 2-D thickness distributions of low absorbing thin films by new laser interferometry

New laser interferometry has been developed for determination of thickness distributions of low absorbing films on transparent substrates. This technique is suitable for films with either a gradual change or a step change in thickness. With this technique we have obtained fringe patterns showing the 2-D thickness distribution of Se films. This technique is simple and nondestructive without involving computations for films with low absorption and substrates transparent to the laser beam.