[2] [2] Papuchon M, Vatoux S. Integrated optical polarizer on LiNbO3: Ti channel waveguides using proton exchange. Electron. Lett., 1983,19(7):612～613

[4] [4] Herrmann H, Muller-Reich P, Reimann V. Integrated optical, TE-and Tm-pass, acoustically tunable double-stage wavelength filers in LiNbO3. Electron. Lett., 1992,28(7):642～644

[5] [5] Feit M D, Fleck J A. Calculations of dispersion in graded-index multimode fibers by a propagating beam-method. Appl. Opt., 1979,18(2):2843～2851

[6] [6] Strake E, Bava G P, Montrosset I. Guided mode of Ti: LiNbO3 channel waveguide. J. Lightwave Technol., 1988,6(6):1126～1134

[7] [7] Mc Wright M, Howerton, Burns W K et al.. Dependence of refractive index on hydrogen concentration in proton exchanged LiNbO3. IEEE J. Quant. Electron., 1991,27(3):593～601

[8] [8] Charczenko W, Januar I, Mickelson A R. Modelling of proton-exchanged and annealed channel waveguides and directional couplers. J. Appl. Phys., 1992,73(1):39～40