OBSERVATION OF FERROELECTRIC 180-DEGREES DOMAINS BY MICROPHOTOMETRY OF HOLOGRAPHIC GRATINGS

A new holographic observation technique for 180 degrees domains is dem onstrated with a cerium-doped strontium barium niobate sample containi ng two antiparallel ferroelectric domains. The method relies on the fa ct that the phase shift of holographically written refractive-index gr atings is +pi/2 or -pi/2 with respect to the initial Light interferenc e pattern depending on the orientation of the domains. As a consequenc e, readout of these gratings creates at the exit face of the sample ne w interference patterns shifted by 0 or pi with respect to the initial one. These patterns, providing an image of the domain structure, are observed by microscope.