New electronic implementation of the timestamps method intended for high resolution comparison of laser wavelengths

This article describes a new measurement system for the comparison of two electronic signals of different frequencies with application to high resolution comparison of laser wavelengths using a Michelson interferometer. It was built within the framework of research projects made by the University of Vigo and the Laboratorio Oficial de Metroloxía de Galicia (LOMG) in cooperation with Escolas Proval High School. The new hardware is based on a cheap high-speed module for the acquisition of data and a microcontroller module for processing, which can also be used for practical lessons in vocational training. The system has been tested with electronic signal generators. The novel measurement method reduces the uncertainty using multiple consecutive measurements and the fractional part of the fringes and could achieve precisions in the range 10−12 of the wavelength ratios.