Sweep Taper Length

Sweep Taper Length#

Find the S-matrix of a taper for different taper lengths

Installation#

pip install meow-sim

Quick Start#

1. Structure#

def create_structures(length=10.0):
    oxide = mw.Structure(
        material=mw.silicon_oxide,
        geometry=mw.Prism(
            poly=np.array([(0, -2.1), (10, -2.1), (10, 2.1), (0, 2.1)]),
            h_min=-3,
            h_max=0,
            axis="y",
        ),
    )

    poly = np.array([(0, -0.45 / 2), (10, -1), (10, 1), (0, 0.45 / 2)])

    core = mw.Structure(
        material=mw.silicon,
        geometry=mw.Prism(
            poly=poly,
            h_min=0,
            h_max=0.22,
            axis="y",
        ),
    )

    structures = [oxide, core]
    return structures

mw.visualize(create_structures())

2. Cells#

def create_cells(length=10.0, cell_length=1.0):
    num_cells = round(length / cell_length)
    structures = create_structures(length=length)
    cells = mw.create_cells(
        structures=structures,
        mesh=mw.Mesh2D(
            x=np.linspace(-2, 2, 101),
            y=np.linspace(-2, 2, 101),
            # specify possible conformal mesh specifications here:
            # bend_radius=2.0,
            # bend_axis=1,
        ),
        Ls=np.array([length / num_cells for _ in range(num_cells)]),
    )
    return cells

cells = create_cells()
mw.visualize(cells[-1])
../_images/cd2a1efbebd669d06a15536ee562ed2815f11d1eb0e3641b09b2cf69573faad8.png

3. Cross Sections#

def create_cross_sections(length=10.0, cell_length=1.0, wl=1.55, T=25.0):
    cells = create_cells(length=length, cell_length=cell_length)
    env = mw.Environment(wl=1.55, T=25.0)
    css = [mw.CrossSection.from_cell(cell=cell, env=env) for cell in cells]
    return css

css = create_cross_sections()
mw.visualize(css[0])
../_images/7e5d3e9af66fb717d181309cde807f31c5a41222bbd95c4483ba035d1821afa9.png

4. Find Modes (FDE)#

def find_modes(length=10.0, cell_length=1.0, wl=1.55, T=25.0, num_modes=10):
    css = create_cross_sections(length=length, cell_length=cell_length, wl=wl, T=T)
    modes: List[List[mw.Mode]] = []
    for cs in tqdm(css):
        modes_in_cs = mw.compute_modes(cs, num_modes=num_modes)
        modes.append(modes_in_cs)
    return modes

5. Calculate S-matrix (EME)#

def find_s_matrix(length=10.0, cell_length=1.0, wl=1.55, T=25.0, num_modes=10):
    modes = find_modes(
        length=length, cell_length=cell_length, wl=wl, T=T, num_modes=num_modes
    )
    S, port_map = mw.compute_s_matrix(modes, cell_lengths=[cell_length for _ in modes])
    return S, port_map

S1, pm1 = find_s_matrix(length=10.0)
S2, pm2 = find_s_matrix(length=5.0)

mw.visualize((abs(S1), pm1))
../_images/355e61ec17f5121f36ae6960e3eb3704633cad17a9432226fd5872672305c50c.png 
mw.visualize((abs(S2), pm2))
../_images/22124882d0ff9baa7d682e1c48ef1f9ebd2f5626eae61504c922279812186554.png
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