my_metasurface

class cemd_metasurf.Metasurface(a=400, b=400, x=0, y=0, z=0, th=1.5707963267948966, eps_b=1, d_layer=0)[source]

Class for defining the metasurface “a” and “b” are the lengths of the lattice vectors (“a” along the x-axis) and “th” is the angle between the lattice vectors. For example the lattice vector “hat(v_1)” and “hat(v_2)” would be: “hat(v_1) = a hat(x)”, “hat(v_2) = b (cos(th)*hat(x) + sin(th)*hat(y))”. Note that “norm(hat(v_1)) = a” and “norm(hat(v_2)) = b”. “x”, “y” and “z” defined the position of the particles in the unit cell. “eps_b” is the backgroud permittivity and the permittivity of the layred substrate (if present). “d_layer” defined the with of the layered substrate (if present).

Parameters:

a (float) – Length lattice vector along the x-axis
b (float) – Length lattice vector along the other axis (defined by the :param th)
x (float or numpy.ndarray) – Position in the x-axis of the particles that composed the unit cell.
y (float or numpy.ndarray) – Position in the y-axis of the particles that composed the unit cell.
z (float or numpy.ndarray) – Position in the z-axis of the particles that composed the unit cell.
th (float) – Angle between lattice vectors.
eps_b – Permittivity of the media.
d_layer – It will defined the width of the layers of the substrate.

set_lattice(a, b, th)[source]

Set the properties of the lattice (lattice vectors and the angle between them).

Parameters:

a (float) – Length lattice vector along the x-axis
b (float) – Length lattice vector along the other axis (defined by the :param th)
th (float) – Angle between lattice vectors.

get_lattice()[source]

Return lattice parameters.

Returns:: tuple with the lattice parameters a, b and th.

set_unit_cell(x, y, z)[source]

Set the position of the particles in the unit cell.

Parameters:

x (float or numpy.ndarray) – Position in the x-axis of the particles that composed the unit cell.
y (float or numpy.ndarray) – Position in the y-axis of the particles that composed the unit cell.
z (float or numpy.ndarray) – Position in the z-axis of the particles that composed the unit cell.

get_unit_cell()[source]

Return unit cell configuration.

Returns:: tuple with the position of the particles in the unit cell (x, y and z)

set_bloch(my_bloch)[source]

Set the actual Bloch wavevector configuration (it takes the last entry of my_bloch). “k” is the wavevector in the medium where the metasurface is placed (k = 2pi/lambda*sqrt(eps_b[0])) By the moment, “eps_b” is a number, but it will be generized in the future for supporting substrates. “kx” and “ky” are the Bloch wavevector (periodicity along the metasurface plane).

Parameters:: my_bloch (classes.BlochWavevector) – The object with the information of the wavevectos

get_bloch()[source]

Return the actual Bloch wave configuration.

Returns:: tuple with the Bloch wave configuration (k, kx and ky)

set_particles(my_particle)[source]

Set all particle to have the properties given by “my_particle”.

Parameters:: my_particle (classes.ParticleMie (or other particle)) – The object with the information of the particle.

set_particle_i(my_particle, i)[source]

Set the particle “i” to have the properties given by “my_particle”.

Parameters:

my_particle (classes.ParticleMie (or other particle).) – The object with the information of the particle.
i (Int) – Index of the particle that will be set.

set_alpha()[source]: Set the polarizability to the one defined in self.particles at the inner wavevector (self.k).

set_alpha_user_defined(alp)[source]

Set the polarizability to a given specific matrix. At the moment is not really used (“set_alpha” is the one used for setting the polarizability for calculating r and t), but in the future I would like to give more flexibility to the code and, for example, being able of easyly set quirality (modify the off-diagonal matrices of alp).

Parameters:: alp (numpy.ndarray) – Polarizability of the system.

class cemd_metasurf.BlochWavevector(k, kx, ky)[source]

Class to handle the Bloch wavevectors “k” is the wavevector (in the medium). “kx” and “ky” are the Bloch wavevector (periodicity along unit cells).

Parameters:

k (float or numpy.ndarray) – Wavevector in the medium.
kx (float or numpy.ndarray) – Bloch wavevector (Floquet periodicity) along the x-axis.
ky (float or numpy.ndarray) – Bloch wavevector (Floquet periodicity) along the y-axis.

get_bloch()[source]

Get the wavevectors.

Returns:: tuple with the Bloch wavevectors (k, kx and ky)

get_bloch_i(i)[source]

Get the wavevector at index “i”

Parameters:: i (Int) – Index of the particle that will be set.
Returns:: tuple with the Bloch wavevectors (k, kx and ky)

class cemd_metasurf.ParticleMie(r_p=1, eps=1, wp=0, wr=0, gr=0)[source]

Class to set the properties of the particle to a Mie particle with a permittivity given by a Drude-Lorentz model (at the moment with one single resonance).

Parameters:

r_p (Float) – Radius of the particles.
ei (Float) – Permittivity at high frecuencies (avobe resonances).
wp (Float (I will generalize it to an array setting several resonances)) – Plasma frequency.
wr (Float (I will generalize it to an array setting several resonances)) – Resonant frequency.
gr (Float (I will generalize it to an array setting several resonances)) – Width of the resonance.