Nulling interferometry by use of geometric phase

Nulling interferometry is a method of detecting a faint source near a bright one, in which destructive interference is realized for the light from the bright source. A nulling interferometer that makes use of geometric phase (Pancharatnam phase) is proposed. An experimental setup is constructed to simulate a stellar interferometer with geometric-phase modulation. We attained extinction of 6 x 10(-5) in white light.