RidgeWaveguide

class modesolverpy.structure.RidgeWaveguide(wavelength, x_step, y_step, wg_height, wg_width, sub_height, sub_width, clad_height, n_sub, n_wg, angle=0, n_clad=1.0, film_thickness='wg_height')

Bases: modesolverpy.structure_base.Slabs

A general ridge waveguide structure.

Parameters:

• wavelength (float) – Wavelength the structure should operate at.
• x_step (float) – The grid step in x that the structure is created on.
• y_step (float) – The grid step in y that the structure is created on.
• wg_height (float) – The height of the ridge.
• wg_width (float) – The width of the ridge.
• sub_height (float) – The thickness of the substrate.
• sub_width (float) – The width of the substrate.
• clad_height (float) – The thickness of the cladding.
• n_sub (float, function) – Refractive index of the substrate. Either a constant (float), or a function that accepts one parameters, the wavelength, and returns a float of the refractive index. This is useful when doing wavelength sweeps and solving for the group velocity. The function provided could be a Sellmeier equation.
• n_wg (float, function) – Refractive index of the waveguide. Either a constant (float), or a function that accepts one parameters, the wavelength, and returns a float of the refractive index. This is useful when doing wavelength sweeps and solving for the group velocity. The function provided could be a Sellmeier equation.
• angle (float) – The angle of the sidewall [degrees] of the waveguide. Default is 0 degrees (vertical sidewalls).
• n_clad (float, function) – Refractive index of the cladding. Either a constant (float), or a function that accepts one parameters, the wavelength, and returns a float of the refractive index. This is useful when doing wavelength sweeps and solving for the group velocity. The function provided could be a Sellmeier equation. Default is air.
• film_thickness (float, str) – The thickness of the film the waveguide is on. If the waveguide is a true ridge (fully etched), then the film thickness can be set to ‘wg_height’, otherwise the waveguide is a rib waveguide, and a float should be given specifying the thickness of the film.

Attributes Summary

eps	np.array – A grid of permittivies representing the permittivity profile of the structure.
eps_func	function – a function that when passed a x and y values, returns the permittivity profile of the structure, interpolating if necessary.
n	np.array – The refractive index profile matrix of the current slab.
n_func	function – a function that when passed a x and y values, returns the refractive index profile of the structure, interpolating if necessary.
x	np.array – The grid points in x.
x_ctr	float – The centre distance in x.
x_pts	int – The number of grid points in x.
xc	np.array – The centre points of the x points.
xc_max	float – The maximum value of xc.
xc_min	float – The minimum value of xc.
xc_pts	int – The number of points in xc.
y	np.array – The grid points in y.
y_ctr	float – The centre distance in y
y_pts	int – The number of grid points in y.
yc	np.array – The centre points of the y points.
yc_max	float – The maximum value of yc.
yc_min	float – The minimum value of yc.
yc_pts	int – The number of points in yc.

Methods Summary

add_slab(height[, n_background, position])	Creates and adds a Slab object.
change_wavelength(wavelength)	Changes the wavelength of the structure.
write_to_file([filename, plot])	Write the refractive index profile to file.

Attributes Documentation

eps

np.array – A grid of permittivies representing the permittivity profile of the structure.

eps_func

function – a function that when passed a x and y values, returns the permittivity profile of the structure, interpolating if necessary.

n

np.array – The refractive index profile matrix of the current slab.

n_func

function – a function that when passed a x and y values, returns the refractive index profile of the structure, interpolating if necessary.

x

np.array – The grid points in x.

x_ctr

float – The centre distance in x.

x_pts

int – The number of grid points in x.

xc

np.array – The centre points of the x points.

xc_max

float – The maximum value of xc.

xc_min

float – The minimum value of xc.

xc_pts

int – The number of points in xc.

y

np.array – The grid points in y.

y_ctr

float – The centre distance in y

y_pts

int – The number of grid points in y.

yc

np.array – The centre points of the y points.

yc_max

float – The maximum value of yc.

yc_min

float – The minimum value of yc.

yc_pts

int – The number of points in yc.

Methods Documentation

add_slab(height, n_background=1.0, position='top')

Creates and adds a Slab object.

Parameters:

• height (float) – Height of the slab.
• n_background (float) – The nominal refractive index of the slab. Default is 1 (air).

Returns:

The name of the slab.

Return type:

str

change_wavelength(wavelength)

Changes the wavelength of the structure.

This will affect the mode solver and potentially the refractive indices used (provided functions were provided as refractive indices).

Parameters:wavelength (float) – The new wavelength.

write_to_file(filename='material_index.dat', plot=True)

Write the refractive index profile to file.

Parameters:

• filename (str) – The nominal filename the refractive index data should be saved to.
• plot (bool) – True if plots should be generates, otherwise False. Default is True.