Lightwave transmissions in the special spot size converters with linear and different nonlinear boundaries were simulated and compared with each other,and the transformation of the mode field distribution with the distance in the optical waveguide spot size converter was analysed.

Based on the characteristic of the beam propagation factor of the diffractive beam from the end surface of dielectric planar waveguide,the rationality of the Gaussian approximation for the mode field distribution of planar waveguide TE0 mode is clarified.

The features of mode field distribution of semiconductor laser were observed with the analysis of the Gauss beam propagation character and the beam ray-trace method.

Development of an automatic system for mode distribution measurement of optical waveguides;

Mode-matching method with PML for field distribution of waveguide;

Using a finite element method, cladding-effective-index and effective mode-index are accurately calculated, and mode distributions in different photonic crystal fiber of various wavelength light are given, the results are consistent with the experiments.

The analysis of mode field distributions of the graded index optical waveguide by the scalar FDTD;

Study of far-field expression and distribution properties of laser diode arrays;