The first part of this manuscript (Chapters 1 to 3) includes all of my work on the dimensional metrology at the nanoscale. After giving an overview of the interferometric instrumentation used in this field and showed their limitations, I present the realization of an interferometer and a laser wavemeter based on elllipsometry. The experimental results showed the possibility of achieving a resolution of 10 pm on a macroscopic range of displacements with the interferometer and a relative accuracy of 10 ⁻ ⁶ on the wavelength with our laser wavemeter for a displacement of the mobile mirror of only 4 μm instead of 150 mm for the conventional scheme. The second part of the manuscript (Chapters 4 to 6) includes all of my work on the mass metrology. After a description of the LNME Watt Balance project whose goal is a redefinition of the kilogram, I report the realization of a polarimetric sensor sensitive to the radial direction of the magnetic field of the permanent magnet component of the Watt Balance and an interferometric inclinometer for the materialization of the gravitational earth axis.
