A study of the possibility of using an adjacent pulse repetition interval length as a scale using a Helium–Neon interferometer

The possibility of using an adjacent pulse repetition interval length (APRIL) as a scale is investigated. Theoretical analysis showed that an APRIL can be used as a standard for a high-accuracy distant evaluation. In an experiment, an APRIL was measured by using a Helium–Neon interferometer, and the measurement was compared with the result of a direct frequency count. The difference was a few hundred nanometers, and thus the APRILʹs effectiveness as a length scale was confirmed. The present concept and analysis pave the way for the development of the remote transfer of APRIL as a length standard via fiber networks.