An epitome for dispersion and buffering in a photonic crystal was set forth. Slots in the form of a line of contacted steeple-houses are implanted in a two-line photonic crystal waveguide (2LPCW) to form an irregular slot of steeple-house defect PCW (SDPCW) to realize bandwidth expanding and a significant regulator for group delay (GD), group velocity dispersion (GVD) and group delay dispersion (GDD) effects. The SDPCW was compared with other types of defects reported in this study and in the literature previously, we fulfilled the highest favorable value of buffering capacity about 210.256 bits. Furthermore, low GDD is achieved in the range from 1 p s 2 to 10 p s 2 for 1mm delay line length. The SDPCW may be appropriate for the workable application, which has a utility in coupling enhancement between the cavities as it was observed from the field distribution detected over confined spatial light along the …