Abstract
The concept of spacial frequency is introduced to characterize suface structures on growing crystals. Growth processes of a salol crystal were studied by the special frequencies which were obtained from in intereference fringe patterns by cross-polarized laser beams. Power spectra of the patterns were obtained from the special frequency spectra which were got by computational Foureir transformation and optical one as well. On the spacial spectrum space, the periodicities of the fringe pattern are indicated by spots and their sequences, and its irreguralities are by diffuseness of the spots. The directions of spot arrays indicate that of the periodicities which are present on the surface. The spacial frequencies of the structure on surfaces will be suitable to characterize growing and as-grown crystal surfaces, etched surfaces and biological matters such as renal stones and pearls. Forthermore a phenomenological theory will be introduced from microscopic ones on the growth by using the concept of the spacial frequeney.
