In the last years, diffraction grating interferometry has been made use of to accurately measure rotational quantities. A new diffraction grating interferometer developed for this purpose was presented in a paper given at the First International Conference on Vibration Measurements by Laser Techniques. Since then, various investigations have been carried out into the behavior of different versions of diffraction grating interferometers based on homodyne and heterodyne techniques. The paper describes these investigations, their results and the uncertainties achieved in measurements of the physical quantities of angular acceleration, angular velocity and rotation angle.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.