예제 #1
0
파일: test.py 프로젝트: mn14tm/Lifetmm
def test():
    # Create structure
    st = LifetimeTmm()
    st.set_vacuum_wavelength(lam0)
    # st.add_layer(1e3, si)
    st.add_layer(1900, sio2)
    st.add_layer(100, si)
    st.add_layer(20, sio2)
    st.add_layer(100, si)
    # st.add_layer(1900, sio2)
    st.add_layer(1e3, air)
    st.info()

    st.set_polarization('TM')
    st.set_field('H')
    st.set_leaky_or_guiding('guiding')
    alpha = st.calc_guided_modes(normalised=True)
    st.set_guided_mode(alpha[0])
    result = st.calc_field_structure()
    z = result['z']
    z = st.calc_z_to_lambda(z)
    E = result['field']
    # Normalise fields
    # E /= max(E)

    plt.figure()
    plt.plot(z, abs(E) ** 2)
    for z in st.get_layer_boundaries()[:-1]:
        z = st.calc_z_to_lambda(z)
        plt.axvline(x=z, color='k', lw=1, ls='--')
    plt.show()
예제 #2
0
파일: test.py 프로젝트: mn14tm/Lifetmm
def guiding_plot():
    """ Find the guiding modes (TE and TM) for a given structure.
    First plot s_11 as a function of beta. When s_11=0 this corresponds
    to a wave guiding mode. We then solve the roots (with scipy's brentq
    algorithm) and plot these as vertical red lines. Check that visually there
    is a red line at each pole so that none are missed.
    """
    # Create structure
    st = LifetimeTmm()
    st.set_vacuum_wavelength(lam0)
    st.set_field('E')
    st.set_leaky_or_guiding('guiding')

    # st.add_layer(0 * lam0, air)
    # st.add_layer(1 * lam0, si)
    # st.add_layer(0 * lam0, air)

    st.add_layer(300, sio2)
    st.add_layer(100, si)
    st.add_layer(20, sio2)
    st.add_layer(100, si)
    st.add_layer(300, air)

    st.info()

    # Prepare the figure
    fig, (ax1, ax2) = plt.subplots(2, 1, sharex='col', sharey='none')

    # TE modes
    st.set_polarization('TE')
    [beta, s_11] = st.s11_guided()
    ax1.plot(beta, s_11, label='TE')
    roots = st.calc_guided_modes(normalised=True)
    for root in roots:
        ax1.axvline(root, color='r')

    # TM modes
    st.set_polarization('TM')
    [beta, s_11] = st.s11_guided()
    ax2.plot(beta, s_11, label='TM')
    roots = st.calc_guided_modes(normalised=True)
    for root in roots:
        ax2.axvline(root, color='r')

    # Format plot
    # fig.tight_layout()
    ax1.set_ylabel('$S_{11}$')
    ax1.axhline(color='k')
    ax2.set_ylabel('$S_{11}$')
    ax2.set_xlabel('Normalised parallel wave vector (k_11/k)')
    ax2.axhline(color='k')
    ax1.legend()
    ax2.legend()
    if SAVE:
        plt.savefig('../Images/guided modes.png', dpi=300)
    plt.show()