Path A — ground state Path B — recoil state Laser pulse plane

Atom Interferometer Fringe Diagram (2D)

Watch a cloud of cold atoms pass through a π/2–π–π/2 laser pulse sequence, drawn as a genuine 2D path diagram instead of a 3D scene: the first pulse splits each atom's matter wave into two paths, the second redirects them so they converge, and the third recombines them at a pair of output ports. Tune the applied acceleration, rotation rate and pulse separation to see how the fringe phase responds — the same physics as the 3D version, drawn flat.