[1] [1] Soref R A. Silicon-based optoelectronics. Proc. IEEE, 1993, 81(12):1687～1706

[3] [3] Soldano L B, Pennings E C M. Optical multi-mode interference based on self-imaging: Principle and applications. J. Lightwave Technol., 1995, 13(4):615～627

[4] [4] Fardad M A, Fallahi M. Sol-gel multimode inteference power splitters. IEEE Photon. Technol. Lett., 1999, 11(6):697～699

[5] [5] Paiann M R, MacDonald R I. Design of phased-array wavelength division multiplexers using multimode interference couplers. Appl. Opt., 1997, 36(21):5097～5108

[6] [6] Leuthold J, Eckner J et al.. Multimode interference couplers for the conversion and combining of zero- and first-order modes. J. Lightwave Technol., 1998, 16(7):1228～1239

[7] [7] Ferreras A, Rodriguez F, Gomez-Salas Z et al.. Useful formulas for multimode interference power splitter/combiner design. IEEE Photon. Technol. Lett., 1999, 5(10):1224～1227

[8] [8] Soref R A, Schmidtchen J, Petermann K. Large single-mode rib waveguides in GeSi/Si and Si-on-SiO2. IEEE J. Quant. Electron., 1991, QE-27(8):1971～1973

[9] [9] Ulrich R. Image formation by phased coincidences in optical waveguides. Opt. Commun., 1975, 13(3):259～264

[10] [10] Bachmann M, Besse P A, Melchior H. General self-imaging properties in N×N multimode interference couplers including phased relations. Appl. Opt., 1994, 33(18):3905～3910

[11] [11] Besse P A, Bachmann M, Melchior H. Phase relations in multimode interference couplers and their application to generalized integrated mach-aehnder optical switches. The Sixth European Conference on Integrated Optics, Neuchatel, Switzerland,1993. 18～22