Na atoms in the group around David E. Pritchard at MIT. Shortly afterwards, an optical version of a Ramsey spectrometer typically used in atomic clocks was recognized also as an atom interferometer at the PTB in Braunschweig, Germany. The largest physical separation between the partial wave packets of atoms was achieved using laser cooling techniques and stimulated Raman transitions by S. Chu and coworkers in Stanford. More recently atom interferometers have begun moving out of laboratory conditions and have begun to address a variety of applications in real word environments. Inertial navigation The first team to make a working model, Pritchard's, was propelled by D.W. Keith. After achieving success, Keith chose to leave atomic physics, in part because one of the most obvious applications for atom interferometry was in highly accurate gyroscopes for submarines carrying ballistic missiles. AIGs (atomic interferometer gyroscopes) and ASGs (atomic spin gyroscopes) use atomic interferometer to sense rotation or in the latter case, uses atomic spin to sense rotation with both having compact size, high precision, and the possibility of being made on a chip-scale. "AI gyros" may compete, along with ASGs, with the established ring laser gyroscope, fiber optic gyroscope and hemispherical resonator gyroscope in future inertial guidance applications. See also Electron interferometer Ramsey interferometry References External links Overview of the atom–light interaction P. R. Berman [Editor], Atom Interferometry. Academic Press (1997). Detailed overview of atom interferometers at that time (good introductions and theory). Stedman Review of the Sagnac Effect Interferometers Articles containing video clips