A tapered waveguide composed of a one-dimensional periodic arrangement of dielectric materialis proposed for light trapping.The equifrequency contours(EFC) of silicon-air multilayer photonic crystals within the first bandgap region are first studied.A zero-group-velocity at the first Brillouin zone boundary along the grating vector is predicted.The propagation constants and eigenfrequencies of the first-order guiding modes are numerically investigated for photonic crystal waveguide structures with a finite thickness.Different frequency components of the guiding modes are found to slov and stop at different thicknesses inside such a tapered waveguide structure.In addition,the time-evolution of a femto-second pulse propagating in the tapered waveguide is also demonstrated.