The coincidence characteristics of the self-imaging multimode interferences of two-dimensional triangle photonic crystal waveguides are investigated by simulation and computation.A two-dimensional photonic crystal 1×2 splitter is proposed.On the basis of self-imaging interference effects
its characteristics are calculated and analyzed by finite-difference time-domain method.Investigations show that the transmissivity of this splitter can be as high as 96% because of the self-imaging effects in the multimode interference region
which can find major potential applications in photonic crystal optical integrated circuits.