[1] [1] Bachmann M, Smit M K, Soldano L B, et al. Polarization-insensitive low-voltage optical waveguide switch using InGaAsP/InP four-port Mach-Zehnder interferometer. in Pro. Conf Fiber Commun,(OFC), San Jose, CA,1993.32～33

[2] [2] Zucker J E, Jones K L, Chiu T H, et al. Strained quantum wells for polarization-independent electroptic waveguide switches. J Lightwave Technol, 1992,10(12): 1926～1930

[3] [3] Porque J, Coudray P, Charters R, et al. WDM based on multimode interference-coupler built in an organic-inorganic material. Opt Commun,2000,183: 45～49

[4] [4] Lierstuen L O, Sudbo A .8-channel wavelength division multiplexer based on multimode interference couplers. IEEE Photo Technol Lett, 1995,7(9): 1034～1036

[5] [5] Paiam M R,MacDonald R I. A 12-channel phased-array wavelength multiplexer with multimode interference couplers.IEEE Photo Technol Lett, 1998,10 (2): 241～243

[6] [6] Roijen R V, Pennings E C M, Stralen M J N, et al. Compact InP-based ring lasers employing multimode interference couplers and combiners. Appl Phys Lett, 1994,64(14): 1753～1755

[7] [7] Bryngdahl O. Image formation using self-imaging techniques. J Opt Soc Amer,1973,63(4): 416～419

[8] [8] Bachmann M, Besse P A, Melchior H. General self-imaging properties in N×N multimode interference couplers including phase relations. Appl Opt,1994,33(18):3905～3911

[9] [9] Bachmann M, Besse P A, Melchior H. Overlapping-image multimode interference couplers with a reduced number of self-images for uniform and nonuniform power splitting. Appl Opt, 1995,34(30):6898～6910

[10] [10] Thoen E R, Molter L A, Donnelly J P. Exact modal analysis and optimization of N×N×1 cascaded waveguide structures with multimode guiding section. IEEE J Quant Electron,1997,33(8):1299～1307