The Turbulent History of Interferometric Methods of Precision Positioning

Precision Positioning advancements over time

Since the earliest developments 150 years ago, advances in light sources, optics, and data processing have firmly established interferometry as an indispensable tool for measurement of distance, displacement, and angle. While it can be sensibly argued that ever-increasing demands on precision have driven advances in interferometric positioning, here we follow the path to the current state of the art with a different driving force in mind: the presence of air in the beam paths, and the innovations required to deal with refractive index changes and air turbulence.