In the frame of telecommunication, surface acoustic waves (SAW) are used to transport information in Radio-Frequency filters (microsystems able to filter an antenna signal). As such filters deal with very low energy (less than 1 mW), it is preferable to prevent any energy leakage during the SAW propagation. Dr Pascal Nicolay and Hugo Chambon wish to understand the causes of such losses in order to optimize these filters. That’s why I had to design and set up an optic device (interferometry) able to measure, with high accuracy and resolution, the amplitude of small wavelength SAW. Of course the CTR could also use it in the future for any other application involving a surface vibration amplitude measurement.