Rigorous coupled-wave analysis

There are two distinct uses of the rigorous coupled-wave analysis code: to create redistribution matrices for the matrix framework, and to define and calculate structures which are treated in their entirety by RCWA (so the matrix framework is not used). The function RCWA is used to create redistribution matrices, while the class rcwa_structure is used to define structures for RCWA calculations.

rayflare.rigorous_coupled_wave_analysis.rcwa.RCWA(structure, size, orders, options, structpath, incidence, transmission, only_incidence_angle=False, prof_layers=None, front_or_rear='front', surf_name='', detail_layer=False, save=True, overwrite=False)

Calculates the reflection/transmission and absorption redistribution matrices for an interface using rigorous coupled-wave analysis.

Parameters:

  • structure – list of Solcore Layer objects for the surface

  • size – tuple with the vectors describing the unit cell: ((x1, y1), (x2, y2))

  • orders – number of RCWA orders to be used for the calculations

  • options – user options (dictionary or State object)

  • structpath – file path where matrices will be stored or loaded from

  • incidence – incidence medium

  • transmission – transmission medium

  • only_incidence_angle – if True, the calculations will only be performed for the incidence theta and phi specified in the options (rest of the matrix will be zeros). CURRENTLY DOES NOT WORK CORRECTLY

  • prof_layers – If no profile calculations are being done, None. Otherwise a list of layers in which the profile should be calculated (front non-incidence medium layer has index 1)

  • front_or_rear – a string, either ‘front’ or ‘rear’; front incidence on the stack, from the incidence medium, or rear incidence on the stack, from the transmission medium.

  • surf_name – name of the surface (to save the matrices generated).

  • detail_layer –

  • save – whether to save the redistribution matrices (True/False), default True

  • overwrite – whether to overwrite existing saved matrices (True/False), default False

Returns:

rayflare.rigorous_coupled_wave_analysis.rcwa.RCWA_structure_wl(wl, geom_list, layers_oc, shapes_oc, s_names, pol, theta, phi, widths, size, orders, A_per_order, S4_options)
rayflare.rigorous_coupled_wave_analysis.rcwa.RCWA_structure_wl_inkstone(wl, geom_list, layers_oc, shapes_oc, s_names, pol, theta, phi, widths, size, orders, *args)
rayflare.rigorous_coupled_wave_analysis.rcwa.RCWA_wl(wl, geom_list, l_oc, s_oc, s_names, pol, theta, phi, widths, size, orders, phi_sym, theta_intv, phi_intv, angle_vector_0, S4_options, layer_details=False, side=1, dist=None)
rayflare.rigorous_coupled_wave_analysis.rcwa.RCWA_wl_inkstone(wl, geom_list, l_oc, s_oc, s_names, pol, theta, phi, widths, size, orders, phi_sym, theta_intv, phi_intv, angle_vector_0, S4_options, layer_details=False, side=1, dist=None)
rayflare.rigorous_coupled_wave_analysis.rcwa.RCWA_wl_prof(wl, rat_output_A, dist, geom_list, layers_oc, shapes_oc, s_names, pol, theta, phi, widths, size, orders, S4_options)
rayflare.rigorous_coupled_wave_analysis.rcwa.RCWA_wl_prof_inkstone(wl, rat_output_A, dist, geom_list, layers_oc, shapes_oc, s_names, pol, theta, phi, widths, size, orders, *args)
rayflare.rigorous_coupled_wave_analysis.rcwa.fold_phi(phis, phi_sym)
rayflare.rigorous_coupled_wave_analysis.rcwa.get_reciprocal_lattice(size, orders)

Returns the reciprocal lattice as defined in S4 (note that this is missing a foctor of 2pi compared to the standard definition).

Parameters:

  • size – lattice vectors in real space ((ax, ay), (bx, by))

  • orders – number of Fourier orders to keep

Returns:

reciprocal lattice (tuple)

Return type:

rayflare.rigorous_coupled_wave_analysis.rcwa.initialise_S(size, orders, geom_list, mats_oc, shapes_oc, shape_mats, widths, options)
rayflare.rigorous_coupled_wave_analysis.rcwa.initialise_S_inkstone(size, orders, geom_list, mats_oc, shapes_oc, shape_mats, widths)
rayflare.rigorous_coupled_wave_analysis.rcwa.necessary_materials(geom_list)
rayflare.rigorous_coupled_wave_analysis.rcwa.process_pol(input_pol)
rayflare.rigorous_coupled_wave_analysis.rcwa.rcwa_absorption_per_layer(S, n_layers, incpf)
rayflare.rigorous_coupled_wave_analysis.rcwa.rcwa_absorption_per_layer_order(S, n_layers, incpf)
rayflare.rigorous_coupled_wave_analysis.rcwa.rcwa_position_resolved(S, layer, depth, incpf)
rayflare.rigorous_coupled_wave_analysis.rcwa.rcwa_rt(S, n_layers)
rayflare.rigorous_coupled_wave_analysis.rcwa.rcwa_rt_pfbo(S, n_layers, incpf, det_l=False)
rayflare.rigorous_coupled_wave_analysis.rcwa.rcwa_rt_pfbo_inkstone(S, n_layers, incpf)
class rayflare.rigorous_coupled_wave_analysis.rcwa.rcwa_structure(structure, size, options, incidence, transmission)

Calculates the reflected, absorbed and transmitted intensity of the structure for the wavelengths and angles defined using an RCWA method implemented using the S4 package.

Parameters:

  • structure –

    A Solcore Structure/SolarCell object with layers and materials. Alternatively, you can supply a list which can contain any mixture of Solcore Layer objects and layers defined in one of the two following ways:

      1. A list of length 4, for materials with a constant refractive index. The list entries are: [width of the layer in nm, real part of refractive index (n), imaginary part of refractive index (k), geometry]

      1. A list of length 5, for materials with a wavelength-dependent refractive index. The list entries are: [width of the layer in nm, wavelengths, n at these wavelengths, k at these wavelengths, geometry]

  • size – tuple with the vectors describing the unit cell: ((x1, y1), (x2, y2))

  • options – dictionary or State object containing user options

  • incidence – semi-infinite incidence medium

  • transmission – semi-infinite transmission medium (substrate)

calculate(options)

Calculates the reflected, absorbed and transmitted intensity of the structure for the wavelengths and angles defined.

Parameters:

options –

options for the calculation. The key entries are:

  • wavelength: Wavelengths (in m) in which calculate the data. An array.

  • theta_in: polar angle (in radians) of the incident light.

  • phi_in: azimuthal angle (in radians) of the incident light.

  • pol: Polarisation of the light: ‘s’, ‘p’ or ‘u’.

  • orders: number of Fourier orders to retain in the RCWA calculation

  • parallel: True of False, whether or not to run simulation on parallel

  • n_jobs: if parallel, specifies how many cores are used. See joblib documentation

  • A_per_order: whether or not to calculate the absorption per diffraction order

  • S4_options: options passed to the S4 solver.

  • RCWA_method: ‘inkstone’ or ‘S4’ (upper/lower case both accepted)

Returns:

A dictionary with the R, A and T at the specified wavelengths and angle.

calculate_profile(options)

It calculates the absorbed energy density within the material.

In principle this has units of [power]/[volume], but we can express it as a multiple of incoming light power density on the material, which has units [power]/[area], so that absorbed energy density has units of 1/[length].’

Parameters:

options – dictionary or State object containing user options

edit_geom_list(layer_index, geom_index, geom_entry)

Allows the user to edit the geom_list of a specific layer in the structure.

Parameters:

  • layer_index – for which layer to edit the geom_list; 0 is the incidence medium

  • geom_index – which entry in that layer’s geom_list to change

  • geom_entry – new entry for the geom_list.

get_fields(layer_index, wavelength, options, extent=None, depth=1e-10, n_points=200, plot=True)

Get the components of the E and H fields at a specific depth in a layer, over a range of x/y points. Can also plot results automatically. Uses the S4 function GetFields().

Parameters:

  • layer_index – index of the layer in which to get epsilon. layer 0 is the incidence medium, layer 1 is the first layer in the stack, etc.

  • wavelength – wavelength (in nm) at which to get epsilon

  • options – dictionary or State object containing user options

  • extent – range of x/y values in format [[x_min, x_max], [y_min, y_max]]. Default is ‘None’, will choose a reasonable area based on the unit cell size by default

  • depth – depth in the layer (from the top of the layer) in nm at which to calculate the fields

  • n_points – number of points to scan across in the x and y directions

  • plot – plot the results (True or False, default True)

Returns:

xs, ys, E, H, E_mag, H_mag. x points, y points, the complex (x, y, z) components of the E field, the complex (x, y, z) components of the H field, the magnitude of the E-field, the magnitude of the H-field. The magnitude is given by sqrt(abs(Ex^2 + Ey^2 + Ez^2))

get_fields_unit_cell(layer_index, wavelength, options, depth=1e-10, n_points=200)

Get the components of the E and H fields at a specific depth in a layer, over a range of x/y points. Can also plot results automatically. Uses the S4 function GetFieldsOnGrid().

Parameters:

  • layer_index – index of the layer in which to get epsilon. layer 0 is the incidence medium, layer 1 is the first layer in the stack, etc.

  • wavelength – wavelength (in nm) at which to get epsilon

  • options – dictionary or State object containing user options

  • depth – depth in the layer (from the top of the layer) in nm at which to calculate the fields

  • n_points – number of points to scan across in the x and y directions

Returns:

xs, ys, E, H, E_mag, H_mag. x points, y points, the complex (x, y, z) components of the E field, the complex (x, y, z) components of the H field, the magnitude of the E-field, the magnitude of the H-field. The magnitude is given by sqrt(abs(Ex^2 + Ey^2 + Ez^2))

get_fields_z_integral(layer_index, wavelength, options, extent=None, n_points=200, plot=True)

Get the magnitude of the E and H fields integrated over z in a layer, over a range of x/y points. Can also plot results automatically.

Parameters:

  • layer_index – index of the layer in which to get epsilon. layer 0 is the incidence medium, layer 1 is the first layer in the stack, etc.

  • wavelength – wavelength (in nm) at which to get epsilon

  • options – dictionary or State object containing user options

  • extent – range of x/y values in format [[x_min, x_max], [y_min, y_max]]. Default is ‘None’, will choose a reasonable area based on the unit cell size by default

  • n_points – number of points to scan across in the x and y directions

  • plot – plot the results (True or False, default True)

Returns:

xs, ys, E, H, E_mag, H_mag. x points, y points, the (x, y, z) amplitudes squared of the E-field (|Ex|^2 etc.), the (x, y, z) amplitudes squared of the H-field (|Ex|^2 etc.) the magnitude of the E-field, the magnitude of the H-field. The magnitude is given by sqrt(abs(Ex^2 + Ey^2 + Ez^2))

get_fourier_epsilon(layer_index, wavelength, options, extent=None, n_points=200, plot=True)

Get the Fourier-decomposed epsilon scanning across x-y points for some layer in the structure for the number of order specified in the options for the structure. Can also plot this automatically.

Parameters:

  • layer_index – index of the layer in which to get epsilon. layer 0 is the incidence medium, layer 1 is the first layer in the stack, etc.

  • wavelength – wavelength (in nm) at which to get epsilon

  • options – dictionary or State object containing user options

  • extent – range of x/y values in format [[x_min, x_max], [y_min, y_max]]. Default is ‘None’, will choose a reasonable area based on the unit cell size by default

  • n_points – number of points to scan across in the x and y directions

  • plot – plot the results (True or False, default True)

Returns:

xs, ys, a_r, a_i. The x points, y points, and the real and imaginary parts of the dielectric function.

make_S(options, wl_ind)
save_layer_postscript(layer_index, options, filename)
set_size(new_size)

Allows the user to set new basis vectors for the structure.

Parameters:

new_size – new basis vectors in the format ((x1, y1), (x2, y2))

set_widths(new_widths)

Allows the user to set new widths for the layers in the structure.

Parameters:

new_widths – new layer widths, in nm.

update_oc(wavelengths)
rayflare.rigorous_coupled_wave_analysis.rcwa.set_incident_wave(S, s, p, options, wavelength)
rayflare.rigorous_coupled_wave_analysis.rcwa.set_incident_wave_inkstone(S, s, p, options, wavelength)