Double-Beam Mach-Zehnder Interferometer Forthin Piezoelectric Films Measurement

This paper describes a Mach-Zehnder double-beam interferometer for measurement of piezoelectric films thickness displacement. The measurement of the sample from both sides with probing beam leads to suppression of bending effect, which can otherwise strongly degrade the results acquired by other methods. The performances of the setup were tested on a reference PZT sample. The measured piezoelectric coefficient was in agreement with its theoretical value. The described setup utilizes minimal number of the optical components which are necessary for controlled phase drift compensation. Further techniques for performance enhancement are also proposed