A novel structure is studied with implanting sporadic slots inside a photonic crystal waveguide (PCW) to form sporadic-slot PCW (SSPCW) for realizing compact, all-optical buffers with lowdispersion, distortion, and attenuation (DDA). We implement the first demonstration that, to the best of our knowledge, the SSPCW works for both TE- and TM-modes all-optical buffers and slow-light waveguides. High buffer performance and wider transmission bandwidth in telecommunication band are obtained, which are guaranteed through bit rate optimization that exceeded 2 Tb/s for both TE and TM modes in ultra-low dispersion region which is 20 times greater than that required for 5G mobile communications and it is also useful for all-optical signal processing. The storage length of 1 bit is obtained as 4:5202 µm for TE mode and 6:0525 µm for TM mode. Moreover, a low relative pulse distortion of 0.0801% µm−1 along the propagation path per unit length is acquired for a 0.63 ps pulse. Besides, the attenuation coefficient of the optical power pulse between the input and output is 0:0170 dB=µm. Additionally, the deigned SSPCW is insensitive for small variations of waveguide parameters and the deviation is virtually negligible between the simulated results and that of the fabricated structures with totally acceptable tolerance below ±3 nm; which is the challenge in the fabrication process of conventional PCW and PCW-cavity.