fiber_ex.py

from photfdtd import Fiber, Grid, Solve

if __name__ == "__main__":
    # Single mode fiber单模光纤模式分析
    # 单模光纤，参数：
    # 包层折射率：1.4437
    # 纤芯折射率：1.4504
    # 纤芯半径：4um
    # Pml边界厚度：3um
    # 波长：1.55um

    background_index = 1.4437

    # 新建一个 grid 对象
    grid = Grid(grid_xlength=200 * 200e-9, grid_ylength=200 * 200e-9, grid_zlength=1, grid_spacing=200e-9,
                foldername="test_fiber", permittivity=background_index ** 2)
    fiber = Fiber(length=1 * 200e-9, radius=[20 * 200e-9, 40 * 200e-9], refractive_index=[1.4504, 1.4555],
                  name='fiber', axis='z', grid=grid)

    # 往 grid 里添加fiber
    grid.add_object(fiber)

    # 创建solve类变量
    solve = Solve(grid=grid,
                  axis="z",
                  filepath=grid.folder,
                  index=0
                  )

    # 绘制折射率分布
    solve.plot()
    # We can plot the geometry now 绘制x=0截面结构图
    grid.save_fig(axis="z", axis_number=0)

    # 计算这个截面处，波长1.55um，折射率3.47附近的2个模式，边界条件选择在四个方向上都是pml，厚度均为15格
    data = solve.calculate_mode(lam=1550e-9, neff=1.4504, neigs=20,
                                x_boundary_low="pml", y_boundary_low="pml",
                                x_boundary_high="pml",
                                y_boundary_high="pml",
                                background_index=background_index)

    # Solve.save_mode(solve.filepath, data)

    Solve.draw_mode(filepath=solve.filepath, data=data, content="amplitude")
    # Solve.draw_mode(filepath=solve.filepath, data=data, content="real_part")
    # Solve.draw_mode(filepath=solve.filepath, data=data, content="imaginary_part")
    # Solve.draw_mode(filepath=solve.filepath, data=data, content="phase")