Abstract. In this paper, we proposed an optical splitter planar waveguide design with super multi channels. The design utilizes the wavefront interference and spatial filtering theory. The DC and AC spatial frequency components of the phase grating are separated spatially, and they are remerged at output plane after specific phase delay is added to the DC spatial frequency component. Therefore, the output field distribution is enhanced in some area and cancelled in the rest area in each period. Finally, the input beam is split into super multi channels. There is only phase modulation in the whole device without any amplitude modulation. Therefore, the insertion loss of the device is very small, theoretically. Besides, for the same branch number, the length of the device is smaller than that of conventional splitters based on Y branch and multimode interference.