Example #1
0
    def setUp(self):

        resolution = 40
        cell_size = mp.Vector3(z=10)

        absorber_layers = [mp.Absorber(1, direction=mp.Z)]

        sources = [mp.Source(src=mp.GaussianSource(1 / 0.803, fwidth=0.1), center=mp.Vector3(),
                             component=mp.Ex)]

        self.sim = mp.Simulation(cell_size=cell_size,
                                 resolution=resolution,
                                 dimensions=1,
                                 default_material=Al,
                                 boundary_layers=absorber_layers,
                                 sources=sources)
Example #2
0
    def test_set_materials(self):
        def change_geom(sim):
            t = sim.meep_time()
            fn = t * 0.02
            geom = [
                mp.Cylinder(radius=3,
                            material=mp.Medium(index=3.5),
                            center=mp.Vector3(fn, fn)),
                mp.Ellipsoid(size=mp.Vector3(1, 2, mp.inf),
                             center=mp.Vector3(fn, fn))
            ]

            sim.set_materials(geometry=geom)

        c = mp.Cylinder(radius=3, material=mp.Medium(index=3.5))
        e = mp.Ellipsoid(size=mp.Vector3(1, 2, mp.inf))

        sources = mp.Source(src=mp.GaussianSource(1, fwidth=0.1),
                            component=mp.Hz,
                            center=mp.Vector3())
        symmetries = [mp.Mirror(mp.X, -1), mp.Mirror(mp.Y, -1)]

        sim = mp.Simulation(cell_size=mp.Vector3(10, 10),
                            geometry=[c, e],
                            boundary_layers=[mp.PML(1.0)],
                            sources=[sources],
                            symmetries=symmetries,
                            resolution=16)

        eps = {'arr1': None, 'arr2': None}

        def get_arr1(sim):
            eps['arr1'] = sim.get_array(mp.Volume(mp.Vector3(),
                                                  mp.Vector3(10, 10)),
                                        component=mp.Dielectric)

        def get_arr2(sim):
            eps['arr2'] = sim.get_array(mp.Volume(mp.Vector3(),
                                                  mp.Vector3(10, 10)),
                                        component=mp.Dielectric)

        sim.run(mp.at_time(50, get_arr1),
                mp.at_time(100, change_geom),
                mp.at_end(get_arr2),
                until=200)

        self.assertFalse(np.array_equal(eps['arr1'], eps['arr2']))
Example #3
0
    def free_space_radiation(self):
        sxy = 4
        dpml = 1
        cell_size = mp.Vector3(sxy + 2 * dpml, sxy + 2 * dpml)

        pml_layers = [mp.PML(dpml)]

        fcen = 1 / self.wvl

        sources = [
            mp.Source(src=mp.GaussianSource(fcen, fwidth=0.2 * fcen),
                      center=mp.Vector3(),
                      component=self.src_cmpt)
        ]

        if self.src_cmpt == mp.Hz:
            symmetries = [mp.Mirror(mp.X, phase=-1), mp.Mirror(mp.Y, phase=-1)]
        elif self.src_cmpt == mp.Ez:
            symmetries = [mp.Mirror(mp.X, phase=+1), mp.Mirror(mp.Y, phase=+1)]
        else:
            symmetries = []

        sim = mp.Simulation(cell_size=cell_size,
                            resolution=self.resolution,
                            sources=sources,
                            symmetries=symmetries,
                            boundary_layers=pml_layers,
                            default_material=mp.Medium(index=self.n))

        nearfield_box = sim.add_near2far(
            fcen, 0, 1,
            mp.Near2FarRegion(center=mp.Vector3(0, +0.5 * sxy),
                              size=mp.Vector3(sxy, 0)),
            mp.Near2FarRegion(center=mp.Vector3(0, -0.5 * sxy),
                              size=mp.Vector3(sxy, 0),
                              weight=-1),
            mp.Near2FarRegion(center=mp.Vector3(+0.5 * sxy, 0),
                              size=mp.Vector3(0, sxy)),
            mp.Near2FarRegion(center=mp.Vector3(-0.5 * sxy, 0),
                              size=mp.Vector3(0, sxy),
                              weight=-1))

        sim.run(until_after_sources=mp.stop_when_dft_decayed())

        Pr = self.radial_flux(sim, nearfield_box, self.r)

        return Pr
Example #4
0
    def test_load_dump_structure(self):
        from meep.materials import Al
        resolution = 50
        cell = mp.Vector3(5, 5)
        sources = mp.Source(src=mp.GaussianSource(1, fwidth=0.2), center=mp.Vector3(), component=mp.Ez)
        one_by_one = mp.Vector3(1, 1, mp.inf)
        geometry = [mp.Block(material=Al, center=mp.Vector3(-1.5, -1.5), size=one_by_one),
                    mp.Block(material=mp.Medium(epsilon=13), center=mp.Vector3(1.5, 1.5), size=one_by_one)]
        pml_layers = [mp.PML(0.5)]

        sim = mp.Simulation(resolution=resolution,
                            cell_size=cell,
                            boundary_layers=pml_layers,
                            geometry=geometry,
                            sources=[sources])

        sample_point = mp.Vector3(0.12, -0.29)
        ref_field_points = []

        def get_ref_field_point(sim):
            p = sim.get_field_point(mp.Ez, sample_point)
            ref_field_points.append(p.real)

        sim.run(mp.at_every(5, get_ref_field_point), until=50)
        dump_fn = 'test_load_dump_structure.h5'
        sim.dump_structure(dump_fn)

        sim = mp.Simulation(resolution=resolution,
                            cell_size=cell,
                            boundary_layers=pml_layers,
                            sources=[sources],
                            load_structure=dump_fn)

        field_points = []

        def get_field_point(sim):
            p = sim.get_field_point(mp.Ez, sample_point)
            field_points.append(p.real)

        sim.run(mp.at_every(5, get_field_point), until=50)

        for ref_pt, pt in zip(ref_field_points, field_points):
            self.assertAlmostEqual(ref_pt, pt)

        mp.all_wait()
        if mp.am_master():
            os.remove(dump_fn)
Example #5
0
    def test_custom_source(self):
        n = 3.4
        w = 1
        r = 1
        pad = 4
        dpml = 2
        sxy = 2 * (r + w + pad + dpml)

        cell = mp.Vector3(sxy, sxy)

        geometry = [
            mp.Cylinder(r + w, material=mp.Medium(index=n)),
            mp.Cylinder(r, material=mp.air)
        ]

        boundary_layers = [mp.PML(dpml)]
        resolution = 10
        fcen = 0.15
        df = 0.1

        # Bump function
        def my_src_func(t):
            if t > 0 and t < 2:
                return math.exp(-1 / (1 - ((t - 1)**2)))
            return 0j

        sources = [
            mp.Source(src=mp.CustomSource(src_func=my_src_func, end_time=100),
                      component=mp.Ez,
                      center=mp.Vector3(r + 0.1))
        ]

        symmetries = [mp.Mirror(mp.Y)]

        sim = mp.Simulation(cell_size=cell,
                            resolution=resolution,
                            geometry=geometry,
                            boundary_layers=boundary_layers,
                            sources=sources,
                            symmetries=symmetries)

        h = mp.Harminv(mp.Ez, mp.Vector3(r + 0.1), fcen, df)
        sim.run(mp.after_sources(h), until_after_sources=200)
        fp = sim.get_field_point(mp.Ez, mp.Vector3(1))

        self.assertAlmostEqual(fp, -0.021997617628500023 + 0j)
Example #6
0
def gaussian_beam(sim, src_time, width, polarization, amplitude=1.0):
    # assume first boundary layer is the full PML
    pml_thickness = sim.boundary_layers[0].thickness
    cell = sim.cell_size

    def amp_func(pos):
        return gaussian_amp(pos, width)

    source = meep.Source(src_time,
                         component=polarization,
                         center=meep.Vector3(0, 0,
                                             -cell[2] / 2 + pml_thickness),
                         size=meep.Vector3(cell[0], cell[1], 0),
                         amplitude=amplitude,
                         amp_func=amp_func)

    sim.add_source(source)
Example #7
0
    def setUp(self):

        resolution = 20
        cell = mp.Vector3(10, 10)
        pml_layers = mp.PML(1.0)
        fcen = 1.0
        df = 1.0
        sources = mp.Source(src=mp.GaussianSource(fcen, fwidth=df),
                            center=mp.Vector3(),
                            component=mp.Ez)

        self.sim = mp.Simulation(resolution=resolution,
                                 cell_size=cell,
                                 boundary_layers=[pml_layers],
                                 sources=[sources])

        fr = mp.ForceRegion(mp.Vector3(y=1.27), mp.Y, size=mp.Vector3(4.38))
        self.myforce = self.sim.add_force(fcen, 0, 1, fr)
Example #8
0
    def setUp(self):

        r = 0.36
        d = 1.4
        sy = 6
        pad = 2
        dpml = 1
        sx = (2 * (pad + dpml + 3)) + d - 1

        cell = mp.Vector3(sx, sy, 0)

        blk = mp.Block(size=mp.Vector3(1e20, 1.2, 1e20),
                       material=mp.Medium(epsilon=13))

        geometry = [blk]

        for i in range(3):
            geometry.append(mp.Cylinder(r, center=mp.Vector3(d / 2 + i)))

        for i in range(3):
            geometry.append(mp.Cylinder(r, center=mp.Vector3(d / -2 - i)))

        sources = [
            mp.Source(mp.GaussianSource(0.25, fwidth=0.2), mp.Hz, mp.Vector3())
        ]

        self.sim = mp.Simulation(cell_size=cell,
                                 geometry=geometry,
                                 sources=sources,
                                 boundary_layers=[mp.PML(dpml)],
                                 resolution=20)

        self.x_min = -0.25 * sx
        self.x_max = +0.25 * sx
        self.y_min = -0.15 * sy
        self.y_max = +0.15 * sy

        self.size_1d = mp.Vector3(self.x_max - self.x_min)
        self.center_1d = mp.Vector3((self.x_min + self.x_max) / 2)

        self.size_2d = mp.Vector3(self.x_max - self.x_min,
                                  self.y_max - self.y_min)
        self.center_2d = mp.Vector3((self.x_min + self.x_max) / 2,
                                    (self.y_min + self.y_max) / 2)
Example #9
0
def main(args):
    sx = 4.0  #spatial extent along x including pmls (μm)
    sy = 4
    sz = 0
    dpml = 1.0

    cell = mp.Vector3(sx, sy, sz)
    pml_layers = [mp.PML(dpml)]
    geometry = [
        mp.Block(mp.Vector3(mp.inf, 0.050, 0),
                 center=mp.Vector3(0, 0.025, 0),
                 material=Ag)
    ]
    resolution = args.res
    wvlmax = 1.0
    fmin = 1 / wvlmax
    wvlmin = 0.100
    fmax = 1 / wvlmin
    wvl = args.wvl
    fcen = 1 / wvl
    df = fmax - fmin
    nfreq = 1
    print("wavelength =", wvl, "μm")
    print("center frequency =", fcen, "1/μm")

    source = [
        mp.Source(mp.GaussianSource(fcen, 0, nfreq),
                  component=mp.Ex,
                  center=mp.Vector3(0, -0.050, 0))
    ]
    symmetries = [mp.Mirror(mp.X), mp.Mirror(mp.Z)]
    sim = mp.Simulation(cell_size=cell,
                        geometry=geometry,
                        sources=source,
                        resolution=resolution,
                        boundary_layers=pml_layers)
    pt = mp.Vector3(0, -0.050, 0)
    sim.run(mp.dft_ldos(fcen, 0, nfreq),
            until_after_sources=mp.stop_when_fields_decayed(
                20, mp.Ex, pt, 1e-3))
    eps_data = sim.get_array(center=mp.Vector3(),
                             size=cell,
                             component=mp.Dielectric)
    ey_data = sim.get_array(center=mp.Vector3(), size=cell, component=mp.Ey)
Example #10
0
    def test_divide_parallel_processes(self):        
        resolution = 20

        sxy = 4
        dpml = 1
        cell = mp.Vector3(sxy+2*dpml,sxy+2*dpml)

        pml_layers = [mp.PML(dpml)]

        n = mp.divide_parallel_processes(2)
        fcen = 1.0/(n+1)

        sources = [mp.Source(src=mp.GaussianSource(fcen,fwidth=0.2*fcen),
                             center=mp.Vector3(),
                             component=mp.Ez)]
        
        symmetries = [mp.Mirror(mp.X),
                      mp.Mirror(mp.Y)]

        self.sim = mp.Simulation(cell_size=cell,
                                 resolution=resolution,
                                 sources=sources,
                                 symmetries=symmetries,
                                 boundary_layers=pml_layers)

    
        flux_box = self.sim.add_flux(fcen, 0, 1,
                                     mp.FluxRegion(mp.Vector3(y=0.5*sxy), size=mp.Vector3(sxy)),
                                     mp.FluxRegion(mp.Vector3(y=-0.5*sxy), size=mp.Vector3(sxy), weight=-1),
                                     mp.FluxRegion(mp.Vector3(0.5*sxy), size=mp.Vector3(y=sxy)),
                                     mp.FluxRegion(mp.Vector3(-0.5*sxy), size=mp.Vector3(y=sxy), weight=-1))

        self.sim.run(until_after_sources=30)

        tot_flux = mp.get_fluxes(flux_box)[0]
        
        tot_fluxes = mp.merge_subgroup_data(tot_flux)
        fcens = mp.merge_subgroup_data(fcen)            

        self.assertEqual(fcens[0],1)
        self.assertEqual(fcens[1],0.5)
        self.assertAlmostEqual(tot_fluxes[0], 9.8628728533)
        self.assertAlmostEqual(tot_fluxes[1], 19.6537275387)
    def test_material_dispersion_with_user_material(self):
        susceptibilities = [
            mp.LorentzianSusceptibility(frequency=1.1, gamma=1e-5, sigma=0.5),
            mp.LorentzianSusceptibility(frequency=0.5, gamma=0.1, sigma=2e-5)
        ]

        def mat_func(p):
            return mp.Medium(epsilon=2.25, E_susceptibilities=susceptibilities)

        fcen = 1.0
        df = 2.0

        sources = mp.Source(mp.GaussianSource(fcen, fwidth=df),
                            component=mp.Ez,
                            center=mp.Vector3())

        kmin = 0.3
        kmax = 2.2
        k_interp = 5

        kpts = mp.interpolate(k_interp, [mp.Vector3(kmin), mp.Vector3(kmax)])

        self.sim = mp.Simulation(cell_size=mp.Vector3(),
                                 geometry=[],
                                 sources=[sources],
                                 material_function=mat_func,
                                 default_material=mp.air,
                                 resolution=20)

        all_freqs = self.sim.run_k_points(200, kpts)
        res = [f.real for fs in all_freqs for f in fs]

        expected = [
            0.1999342026399106,
            0.41053963810375294,
            0.6202409070451909,
            0.8285737385146619,
            1.0350739448523063,
            1.2392775309110078,
            1.4407208712852109,
        ]

        np.testing.assert_allclose(expected, res)
Example #12
0
    def setUp(cls):
        cls.resolution = 20  # pixels/μm
        cls.dpml = 0.5  # thickness of PML
        cls.L = 6.0  # length of non-PML region
        cls.n = 2.4  # refractive index of surrounding medium
        cls.wvl = 1.0  # wavelength (in vacuum)

        cls.fcen = 1 / cls.wvl
        cls.sources = [
            mp.Source(src=mp.GaussianSource(cls.fcen, fwidth=0.2 * cls.fcen),
                      component=mp.Ex,
                      center=mp.Vector3())
        ]

        cls.symmetries = [
            mp.Mirror(direction=mp.X, phase=-1),
            mp.Mirror(direction=mp.Y),
            mp.Mirror(direction=mp.Z)
        ]
Example #13
0
    def test_absorber_2d(self):
        source = mp.Source(
            src=mp.GaussianSource(frequency=0.1, fwidth=0.1),
            component=mp.Hz,
            center=mp.Vector3()
        )

        sim = mp.Simulation(
            cell_size=mp.Vector3(20, 20, 0),
            resolution=10,
            sources=[source],
            boundary_layers=[mp.Absorber(5)]
        )

        sim.run(until_after_sources=1000)
        v = mp.Vector3(4.13, 3.75, 0)
        p = sim.get_field_point(mp.Hz, v)

        self.assertAlmostEqual(-4.058476603571745e-11, p.real)
Example #14
0
def main():
    n = 3.4  # index of waveguide
    w = 1  # width of waveguide
    r = 1  # inner radius of ring
    pad = 4  # padding between waveguide and edge of PML
    dpml = 2  # thickness of PML
    sxy = 2 * (r + w + pad + dpml)  # cell size

    # Create a ring waveguide by two overlapping cylinders - later objects
    # take precedence over earlier objects, so we put the outer cylinder first.
    # and the inner (air) cylinder second.

    c1 = mp.Cylinder(radius=r + w, material=mp.Medium(index=n))
    c2 = mp.Cylinder(radius=r)

    # If we don't want to excite a specific mode symmetry, we can just
    # put a single point source at some arbitrary place, pointing in some
    # arbitrary direction.  We will only look for Ez-polarized modes.

    fcen = 0.15  # pulse center frequency
    df = 0.1  # pulse width (in frequency)

    src = mp.Source(mp.GaussianSource(fcen, fwidth=df), mp.Hz, mp.Vector3(r + 0.1))

    sim = mp.Simulation(cell_size=mp.Vector3(sxy, sxy),
                        geometry=[c1, c2],
                        sources=[src],
                        resolution=10,
                        symmetries=[mp.Mirror(mp.Y)],
                        boundary_layers=[mp.PML(dpml)])

    h = mp.Harminv(mp.Ex, mp.Vector3(r + 0.1), fcen, df)
    sim.run(mp.after_sources(h), until_after_sources=200)

    print(f'Harminv found {len(h.modes)} resonant modes(s).')
    for mode in h.modes:
        print(f'The resonant mode with f={mode.freq} has Q={mode.Q}')

    sim.plot2D(fields=mp.Ex,
           field_parameters={'alpha':0.8, 'cmap':'RdBu', 'interpolation':'none'},
           boundary_parameters={'hatch':'o', 'linewidth':1.5, 'facecolor':'y', 'edgecolor':'b', 'alpha':0.3})
    plt.show()
Example #15
0
    def place_adjoint_sources(self, qweights):

        # extract temporal envelope of forward sources from existing simulation
        envelope = self.sim.sources[0].src
        freq     = envelope.frequency
        omega    = 2.0*np.pi*freq
        factor   = 2.0j*omega
        if callable(getattr(envelope, "fourier_transform", None)):
            factor /= envelope.fourier_transform(freq)

        ##################################################
        # loop over all objective quantities, adding
        # appropriately-weighted adjoint sources for each
        # quantity
        ##################################################
        self.sim.reset_meep()
        self.sim.change_sources([])
        nf=0
        for qr, qw in zip(self.obj_func.qrules, qweights):

            if qw==0.0:
                continue

            code, mode, cell=qr.code, qr.mode, self.dft_cells[qr.ncell]
            EH =      cell.get_EH_slices(nf=nf, label='forward')  if mode==0 \
                 else cell.get_eigenfield_slices(mode=mode, nf=0)

            components  = cell.components
            x, y, z, w  = cell.xyzw[0], cell.xyzw[1], cell.xyzw[2], cell.xyzw[3]
            shape       = [np.shape(q)[0] for q in [x,y,z]]

            if code in 'PM':
                sign = 1.0 if code=='P' else -1.0
                signs=[+1.0,-1.0,+1.0*sign,-1.0*sign]
                self.sim.sources+=[mp.Source(envelope, cell.components[3-nc],
                                             cell.center, cell.size,
                                             amplitude=signs[nc]*factor*qw,
                                             amp_data=np.reshape(np.conj(EH[nc]),shape)
                                            ) for nc in range(len(components))
                                  ]

        self.sim.force_complex_fields=True
Example #16
0
def main():
    # Some parameters to describe the geometry:
    eps = 13  # dielectric constant of waveguide
    w = 1.2  # width of waveguide
    r = 0.36  # radius of holes

    # The cell dimensions
    sy = 12  # size of cell in y direction (perpendicular to wvg.)
    dpml = 1  # PML thickness (y direction only!)

    cell = mp.Vector3(1, sy)

    b = mp.Block(size=mp.Vector3(mp.inf, w, mp.inf), material=mp.Medium(epsilon=eps))
    c = mp.Cylinder(radius=r)

    fcen = 0.25  # pulse center frequency
    df = 1.5  # pulse freq. width: large df = short impulse

    s = mp.Source(src=mp.GaussianSource(fcen, fwidth=df), component=mp.Hz,
                  center=mp.Vector3(0.1234))

    sym = mp.Mirror(direction=mp.Y, phase=-1)

    sim = mp.Simulation(cell_size=cell, geometry=[b, c], sources=[s], symmetries=[sym],
                        boundary_layers=[mp.PML(dpml, direction=mp.Y)], resolution=20)

    kx = False  # if true, do run at specified kx and get fields
    k_interp = 19  # # k-points to interpolate, otherwise

    if kx:
        sim.k_point = mp.Vector3(kx)

        sim.run(
            mp.at_beginning(mp.output_epsilon),
            mp.after_sources(mp.Harminv(mp.Hz, mp.Vector3(0.1234), fcen, df)),
            until_after_sources=300
        )

        sim.run(mp.at_every(1 / fcen / 20, mp.output_hfield_z), until=1 / fcen)

    else:
        sim.run_k_points(300, mp.interpolate(k_interp, [mp.Vector3(), mp.Vector3(0.5)]))
Example #17
0
    def setUp(self):
        resolution = 50
        sxy = 4
        dpml = 1
        cell = mp.Vector3(sxy + 2 * dpml, sxy + 2 * dpml, 0)

        pml_layers = mp.PML(dpml)

        fcen = 1.0
        df = 0.4
        self.src_cmpt = mp.Ez

        sources = mp.Source(
            src=mp.GaussianSource(fcen, fwidth=df),
            center=mp.Vector3(),
            component=self.src_cmpt
        )

        if self.src_cmpt == mp.Ex:
            symmetries = [mp.Mirror(mp.Y)]
        elif self.src_cmpt == mp.Ey:
            symmetries = [mp.Mirror(mp.X)]
        elif self.src_cmpt == mp.Ez:
            symmetries = [mp.Mirror(mp.X), mp.Mirror(mp.Y)]

        self.sim = mp.Simulation(
            cell_size=cell,
            resolution=resolution,
            sources=[sources],
            symmetries=symmetries,
            boundary_layers=[pml_layers]
        )

        self.nearfield = self.sim.add_near2far(
            fcen,
            0,
            1,
            mp.Near2FarRegion(mp.Vector3(0, 0.5 * sxy), size=mp.Vector3(sxy)),
            mp.Near2FarRegion(mp.Vector3(0, -0.5 * sxy), size=mp.Vector3(sxy), weight=-1.0),
            mp.Near2FarRegion(mp.Vector3(0.5 * sxy), size=mp.Vector3(0, sxy)),
            mp.Near2FarRegion(mp.Vector3(-0.5 * sxy), size=mp.Vector3(0, sxy), weight=-1.0)
        )
Example #18
0
    def setUp(self):
        resolution = 20

        cell = mp.Vector3(10, 10, 0)

        pml_layers = mp.PML(1.0)

        self.fcen = 1.0
        df = 1.0

        sources = mp.Source(src=mp.GaussianSource(self.fcen, fwidth=df), center=mp.Vector3(),
                            component=mp.Ez)

        symmetries = [mp.Mirror(mp.X), mp.Mirror(mp.Y)]

        self.sim = mp.Simulation(resolution=resolution,
                                 cell_size=cell,
                                 boundary_layers=[pml_layers],
                                 sources=[sources],
                                 symmetries=symmetries)
Example #19
0
def main(args):
    sx = 4.0  #spatial extent along x including pmls (μm)
    sy = 4.0
    sz = 4.0
    dpml = 1.0

    cell = mp.Vector3(sx, sy, sz)
    pml_layers = [mp.PML(dpml)]
    geometry = [
        mp.Sphere(radius=0.7, center=mp.Vector3(0, 0, 0), material=Graph),
        mp.Sphere(radius=0.5,
                  center=mp.Vector3(0, 0, 0),
                  material=mp.Medium(epsilon=12.25))
    ]
    resolution = args.res
    wvl = args.wvl / 1000  #convert args.wvl from nm to μm
    fcen = 1 / wvl
    df = 0.1 * fcen
    nfreq = 1
    print("wavelength =", wvl, "μm")
    print("center frequency =", fcen, "1/μm")

    source = [
        mp.Source(mp.GaussianSource(fcen, df, nfreq),
                  component=mp.Ex,
                  center=mp.Vector3(0, 0.705, 0))
    ]

    symmetries = [mp.Mirror(mp.X), mp.Mirror(mp.Z)]

    sim = mp.Simulation(cell_size=cell,
                        geometry=geometry,
                        sources=source,
                        resolution=resolution,
                        boundary_layers=pml_layers)

    pt = mp.Vector3(0, 0.75, 0)

    sim.run(mp.dft_ldos(fcen, df, nfreq),
            until_after_sources=mp.stop_when_fields_decayed(
                20, mp.Ex, pt, 1e-9))
Example #20
0
File: ring.py Project: liyycat/meep
def main():
    n = 3.4  # index of waveguide
    w = 1  # width of waveguide
    r = 1  # inner radius of ring
    pad = 4  # padding between waveguide and edge of PML
    dpml = 2  # thickness of PML
    sxy = 2 * (r + w + pad + dpml)  # cell size

    # Create a ring waveguide by two overlapping cylinders - later objects
    # take precedence over earlier objects, so we put the outer cylinder first.
    # and the inner (air) cylinder second.

    c1 = mp.Cylinder(radius=r + w, material=mp.Medium(index=n))
    c2 = mp.Cylinder(radius=r)

    # If we don't want to excite a specific mode symmetry, we can just
    # put a single point source at some arbitrary place, pointing in some
    # arbitrary direction.  We will only look for Ez-polarized modes.

    fcen = 0.15  # pulse center frequency
    df = 0.1  # pulse width (in frequency)

    src = mp.Source(mp.GaussianSource(fcen, fwidth=df), mp.Ez, mp.Vector3(r + 0.1))

    sim = mp.Simulation(cell_size=mp.Vector3(sxy, sxy),
                        geometry=[c1, c2],
                        sources=[src],
                        resolution=10,
                        symmetries=[mp.Mirror(mp.Y)],
                        boundary_layers=[mp.PML(dpml)])

    sim.run(
        mp.at_beginning(mp.output_epsilon),
        mp.after_sources(mp.Harminv(mp.Ez, mp.Vector3(r + 0.1), fcen, df)),
        until_after_sources=300
    )

    # Output fields for one period at the end.  (If we output
    # at a single time, we might accidentally catch the Ez field when it is
    # almost zero and get a distorted view.)
    sim.run(mp.at_every((1 / fcen / 20), mp.output_efield_z), until=(1 / fcen))
Example #21
0
    def setUp(self):
        n = 3.4
        w = 1
        self.r = 1
        pad = 4
        dpml = 2
        sr = self.r + w + pad + dpml
        dimensions = mp.CYLINDRICAL
        cell = mp.Vector3(sr, 0, 0)
        m = 3

        geometry = [
            mp.Block(
                center=mp.Vector3(self.r + (w / 2)),
                size=mp.Vector3(w, mp.inf, mp.inf),
                material=mp.Medium(index=n)
            )
        ]

        pml_layers = [mp.PML(dpml)]
        resolution = 10

        self.fcen = 0.15
        self.df = 0.1
        sources = [
            mp.Source(
                src=mp.GaussianSource(self.fcen, fwidth=self.df),
                component=mp.Ez,
                center=mp.Vector3(self.r + 0.1)
            )
        ]

        self.sim = mp.Simulation(
            cell_size=cell,
            geometry=geometry,
            boundary_layers=pml_layers,
            resolution=resolution,
            sources=sources,
            dimensions=dimensions,
            m=m
        )
Example #22
0
    def test_eigfreq(self):
        w = 1.2  # width of waveguide
        r = 0.36  # radius of holes
        d = 1.4  # defect spacing (ordinary spacing = 1)
        N = 3  # number of holes on either side of defect
        sy = 6  # size of cell in y direction (perpendicular to wvg.)
        pad = 2  # padding between last hole and PML edge
        dpml = 1  # PML thickness
        sx = 2 * (pad + dpml + N) + d - 1  # size of cell in x direction

        geometry = [
            mp.Block(size=mp.Vector3(mp.inf, w, mp.inf),
                     material=mp.Medium(epsilon=13))
        ]
        for i in range(N):
            geometry.append(mp.Cylinder(r, center=mp.Vector3(d / 2 + i)))
            geometry.append(mp.Cylinder(r, center=mp.Vector3(-(d / 2 + i))))

        fcen = 0.25
        df = 0.2
        src = [
            mp.Source(mp.GaussianSource(fcen, fwidth=df),
                      component=mp.Hz,
                      center=mp.Vector3(0),
                      size=mp.Vector3(0, 0))
        ]

        sim = mp.Simulation(
            cell_size=mp.Vector3(sx, sy),
            force_complex_fields=True,
            geometry=geometry,
            boundary_layers=[mp.PML(1.0)],
            sources=src,
            symmetries=[mp.Mirror(mp.X, phase=-1),
                        mp.Mirror(mp.Y, phase=-1)],
            resolution=20)
        sim.init_sim()
        eigfreq = sim.solve_eigfreq(tol=1e-6)

        self.assertAlmostEqual(eigfreq.real, 0.23445413142440263, places=5)
        self.assertAlmostEqual(eigfreq.imag, -0.0003147775697388, places=5)
Example #23
0
    def init_simple_simulation(self, **kwargs):
        resolution = 20

        cell = mp.Vector3(10, 10)

        pml_layers = mp.PML(1.0)

        fcen = 1.0
        df = 1.0

        sources = mp.Source(src=mp.GaussianSource(fcen, fwidth=df), center=mp.Vector3(),
                            component=mp.Ez)

        symmetries = [mp.Mirror(mp.X), mp.Mirror(mp.Y)]

        return mp.Simulation(resolution=resolution,
                             cell_size=cell,
                             boundary_layers=[pml_layers],
                             sources=[sources],
                             symmetries=symmetries,
                             **kwargs)
Example #24
0
    def setUp(self):
        cell = mp.Vector3(1, 12)
        b = mp.Block(size=mp.Vector3(1e20, 1.2, 1e20),
                     material=mp.Medium(epsilon=13))
        c = mp.Cylinder(0.36)

        self.fcen = 0.25
        self.df = 1.5

        s = mp.Source(src=mp.GaussianSource(self.fcen, fwidth=self.df),
                      component=mp.Hz,
                      center=mp.Vector3(0.1234))

        sym = mp.Mirror(direction=mp.Y, phase=-1)

        self.sim = mp.Simulation(cell_size=cell,
                                 geometry=[b, c],
                                 sources=[s],
                                 symmetries=[sym],
                                 boundary_layers=[mp.PML(1, direction=mp.Y)],
                                 resolution=20)
Example #25
0
def createDiffractionSlit():
    cell = mp.Vector3(globalVariables.waveguideXSize, globalVariables.waveguideYSize, 0)

    geometry = [mp.Block(mp.Vector3(1e20, 1, 1e20),
                     center=mp.Vector3(0, 0),
                         material=mp.Medium(epsilon=globalVariables.epsilonOfMaterial)),
                mp.Block(mp.Vector3(globalVariables.blockXSize,globalVariables.blockYSize,0),
                         center=mp.Vector3(0,(globalVariables.blockYSize-globalVariables.waveguideYSize)/2.0,0),
                         material=mp.Medium(epsilon=globalVariables.epsilonOfBoundary)),
                mp.Block(mp.Vector3(globalVariables.blockXSize,globalVariables.blockYSize,0),
                         center=mp.Vector3(0,(globalVariables.waveguideYSize-globalVariables.blockYSize)/2.0,0),
                         material=mp.Medium(epsilon=globalVariables.epsilonOfBoundary))]


    sources = [mp.Source(mp.ContinuousSource(frequency=0.15),
                     component=mp.Ez,
                         center=mp.Vector3(-globalVariables.waveguideXSize/2+1,0,0))]

    pml_layers = [mp.PML(1.0)]

    return cell,geometry,sources,pml_layers
Example #26
0
    def test_physical(self):

        a = 10.0
        ymax = 3.0
        xmax = 8.0
        dx = 2.0
        w = 0.30

        cell_size = mp.Vector3(xmax, ymax)
        pml_layers = [mp.PML(ymax / 3.0)]

        sources = [
            mp.Source(src=mp.ContinuousSource(w),
                      component=mp.Ez,
                      center=mp.Vector3(-dx),
                      size=mp.Vector3())
        ]

        sim = mp.Simulation(cell_size=cell_size,
                            resolution=a,
                            boundary_layers=pml_layers,
                            sources=sources,
                            force_complex_fields=True)
        sim.init_sim()
        sim.solve_cw(tol=1e-5 if mp.is_single_precision() else 1e-6)

        p1 = mp.Vector3()
        p2 = mp.Vector3(dx)

        amp1 = sim.get_field_point(mp.Ez, p1)
        amp2 = sim.get_field_point(mp.Ez, p2)

        ratio = abs(amp1) / abs(amp2)
        ratio = ratio**2  # in 2d, decay is ~1/sqrt(r), so square to get 1/r

        fail_fmt = "Failed: amp1 = ({}, {}), amp2 = ({}, {})\nabs(amp1/amp2){} = {}, too far from 2.0"
        fail_msg = fail_fmt.format(amp1.real, amp1, amp2.real, amp2, "^2",
                                   ratio)

        self.assertTrue(ratio <= 2.12 and ratio >= 1.88, fail_msg)
Example #27
0
def main(args):
    resolution = 20 # 20 pixels per unit 1 um
    eps = 80 # epsilon of cylinder medium
    Mat1 = mp.Medium(epsilon=eps) # definition of the material
    dimensions = mp.CYLINDRICAL

    r = args.r # the value of cylinder radius
    rl = args.rl # the r/l ration is given, to obtain the l value l=r/rl
    x = args.x
    dpml = args.dpml
    dair = args.dair
    m=args.m

    w=1*x  
    h = r/rl # the height of the cylinder
    sr = r + dair + dpml
    sz = h + 2*dair + 2*dpml
    w_max=1.8
    w_min=0.2
    dw=w_max-w_min

    boundary_layers = [mp.PML(dpml)]
    Cyl = mp.Cylinder(material=Mat1, radius=r, height=h, center=mp.Vector3(0,0,0)) # make a cylinder with given parameters
    geometry = [Cyl]
    cell_size = mp.Vector3(sr,0,sz)

    #sources = [ mp.Source(mp.ContinuousSource(frequency = w), component=mp.Hz, center=mp.Vector3(r+dair,0,0)) ]
    sources = [mp.Source(mp.GaussianSource(w, fwidth=dw), component=mp.Hz, center=mp.Vector3(r+dair,0,0))]
    sim = mp.Simulation(resolution=resolution,
                        cell_size=cell_size,
                        boundary_layers=boundary_layers,
                        geometry=geometry,
                        sources=sources,
                        dimensions=dimensions,
                        m=m)
    sim.run(mp.in_volume(mp.Volume(center=mp.Vector3(), size=mp.Vector3(sr,0,sz)),
            mp.at_end(mp.output_epsilon, mp.output_efield_z)),
            mp.after_sources(mp.Harminv(mp.Hz, mp.Vector3(), w, dw)),
            until_after_sources=100)
    def test_integrated_source(self):
        sources = [
            mp.Source(mp.ContinuousSource(1, is_integrated=True),
                      center=mp.Vector3(-2),
                      size=mp.Vector3(y=6),
                      component=mp.Ez)
        ]
        sim = mp.Simulation(resolution=20,
                            cell_size=(6, 6),
                            boundary_layers=[mp.PML(thickness=1)],
                            sources=sources,
                            k_point=mp.Vector3())
        sim.run(until=30)

        # field in mid-plane should be nearly constant,
        # so compute its normalized std. dev. and check << 1
        ez = sim.get_array(mp.Ez, center=mp.Vector3(2), size=mp.Vector3(y=6))
        std = np.std(ez) / np.sqrt(np.mean(ez**2))
        print("std = ", std)
        self.assertAlmostEqual(std,
                               0.0,
                               places=4 if mp.is_single_precision() else 8)
Example #29
0
    def test_geometry_center(self):
        resolution = 20
        cell_size = mp.Vector3(10, 10)
        pml = [mp.PML(1)]
        center = mp.Vector3(2, -1)
        result = []
        fcen = 0.15
        df = 0.1

        sources = [mp.Source(src=mp.GaussianSource(fcen, fwidth=df), component=mp.Ez,
                             center=mp.Vector3())]
        geometry = [mp.Block(center=mp.Vector3(), size=mp.Vector3(mp.inf, 3, mp.inf),
                             material=mp.Medium(epsilon=12))]

        def print_field(sim):
            result.append(sim.get_field_point(mp.Ez, mp.Vector3(2, -1)))

        sim = mp.Simulation(resolution=resolution, cell_size=cell_size, boundary_layers=pml,
                            sources=sources, geometry=geometry, geometry_center=center)
        sim.run(mp.at_end(print_field), until=50)

        self.assertAlmostEqual(result[0], -0.0599602798684155)
Example #30
0
    def test_load_dump_structure(self):
        resolution = 10
        cell = mp.Vector3(10, 10)
        pml_layers = mp.PML(1.0)
        fcen = 1.0
        df = 1.0
        sources = mp.Source(src=mp.GaussianSource(fcen, fwidth=df),
                            center=mp.Vector3(),
                            component=mp.Hz)
        geometry = mp.Cylinder(0.2, material=mp.Medium(index=3))

        sim = mp.Simulation(resolution=resolution,
                            cell_size=cell,
                            default_material=mp.Medium(index=1),
                            geometry=[geometry],
                            boundary_layers=[pml_layers],
                            sources=[sources])

        sim.run(until=200)
        ref_field = sim.get_field_point(mp.Hz, mp.Vector3(z=2))
        dump_fn = 'test_load_dump_structure.h5'
        sim.dump_structure(dump_fn)

        sim = mp.Simulation(resolution=resolution,
                            cell_size=cell,
                            default_material=mp.Medium(index=1),
                            geometry=[],
                            boundary_layers=[pml_layers],
                            sources=[sources],
                            load_structure=dump_fn)
        sim.run(until=200)
        field = sim.get_field_point(mp.Hz, mp.Vector3(z=2))

        self.assertAlmostEqual(ref_field, field)

        mp.all_wait()
        if mp.am_master():
            os.remove(dump_fn)