Fig. 1. (a) Bandgap structure of periodic lattice; (b) energy flow versus propagation constant for first-order, triple-order and fifth-order gap solitons with p=16, Ω=2.067 and S=0.5; (c) energy flow versus propagation constant for second-order, four-order and sixth-order gap solitons with p=16, Ω=2.067 and S=0.5; (d) propagation constant versus optical lattice's depth for triple-order gap soliton with Ω=2.067 and S=0.5

Fig. 2. (a) Profile of first-order gap solitons with b=12.50; profile of triple-order gap solitons with (b) b=11.80 and (c) b=12.60; (d) profile of fifth-order gap solitons with b=11.80

Fig. 3. (a) Profile of second-order gap solitons with b=12.50; profile of fourth-order gap solitons with (b) b=11.80 and (c) b=12.60; (d) profile of sixth-order gap solitons with b=11.80

Fig. 4. (a) Propagation of third-order gap solitons corresponding to Fig. 2(c); (b) propagation of sixth-order gap solitons corresponding to Fig. 3(d); (c) perturbation eigenvalue spectrum of third-order gap solitons corresponding to Fig. 2(c); (d) perturbation growth rate Re(δ) versus propagation constant for sixth-order gap solitons in region of 11.60