Topographic investigation of ferroelectric domain structures in periodically-poled lithium niobate crystals by a profilometer

A topographic investigation of periodically poled lithium niobate (PPLN) crystals was performed by recording a map of the crystal surface after a selective etching process using a standard profilometer. A procedure to correct for the systematic error introduced by the finite size of the tip is discussed in detail so that the width of ferroelectric domains can be mapped with an estimated tolerance of about 3% along the whole length of the sample. The method is applied to a PPLN structure obtained by the Czochralski off-center technique.