Application of Jamin interferometer for the determination of thin transparent polymer films thickness in the visible range

Modification of the technique for thickness determination of thin polymer films that are transparent in the visible range with the application of Jamin interferometer is suggested. The films are deposited on glass substrate. The technique is based on measuring the relative shift of interference fringes. The distinguishing feature of the approach is the use of three beams, one of which participates in the formation of the reference signal; the interference-fringe shift is estimated by the analysis of brightness curves.