Abstract
Recently, nonlinear guided-optical phenomena have attracted the attention of many workers to establish the all-optical signal processing. As one of the nonlinear media, the Kerr-type medium whose refractive index depends on the light intensity is usually used. This medium shows the interesting phenomena such as self-focusing, generation of self-phase modulation and optical bistability [1], [2]. The grating couplers are one of the most important elements for the optical integrated circuits. Under some approximations, the mode conversions [3], the beam scanner [4], [5] and the optical bistability [6], [7] are examined. For the more complete interpretation of the properties of the nonlinear grating couplers, the precise analysis is needed.