meta.shockley.
ThresholdSearch2D
(name='')¶Solver for threshold search of semiconductor laser.
This solver performs thermoelectrical computations followed by
determination ot threshold current and optical analysis in order to
determine the threshold of a semiconductor laser. The search is
performed by scipy
root finding algorithm in order to determine
the voltage and electric current ensuring no optical loss in the
laser cavity.
The computations can be executed using compute method, after which
the results may be save to the HDF5 file with save or presented visually
using plot_...
methods. If save
parameter of the compute()
method
is True the fields are saved automatically after the computations.
The file name is based on the name of the executed script with suffix denoting
either the launch time or the identifier of a batch job if a batch system
(like SLURM, OpenPBS, or SGE) is used.
compute ([save, invalidate, group, stepsave]) 
Execute the algorithm. 
compute_thermoelectric () 
Perform thermoelectric calculations. 
get_gain_spectrum (lams[, pos, junction]) 
Get gain spectrum for specified junction. 
get_junction_concentrations ([interpolation]) 
Get carriers concentration at the active regions. 
get_junction_currents ([refine, interpolation]) 
Get current densities at the active regions. 
get_junction_gains ([axis, interpolation]) 
Get gain at the active regions. 
get_lam () 

get_nng () 
Get approximate effective index for optical computations. 
get_optical_determinant (neff) 
Function computing determinant of the optical solver. 
get_optical_field ([resolution]) 
Get computed optical mode field at threshold. 
get_optical_field_horizontal ([resolution, …]) 
Get horizontal distribution of the computed optical mode field at threshold. 
get_optical_field_vertical ([pos, offset, …]) 
Plot vertical distribution of the computed optical mode field at threshold and refractive index profile. 
get_temperature () 
Get temperature on a thermal mesh. 
get_total_current ([nact]) 
Get total current flowing through active region [mA] 
get_vert_optical_determinant (vneff) 
Function computing ‘vertical determinant’ of the optical solver. 
get_vertical_voltage ([at]) 
Get computed voltage along the vertical axis. 
get_voltage () 
Get voltage on an electrical mesh. 
initialize () 
Initialize solver. 
invalidate () 
Set the solver back to uninitialized state. 
plot_gain_spectrum (lams[, pos, junction, comp]) 
Plot gain spectrum for specified junction. 
plot_junction_concentration ([bounds, …]) 
Plot carriers concentration at the active region. 
plot_junction_current ([refine, bounds, …]) 
Plot current density at the active region. 
plot_junction_gain ([axis, bounds, …]) 
Plot gain at the active region. 
plot_optical_determinant (neffs, **kwargs) 
Function plotting determinant of the optical solver. 
plot_optical_field ([resolution, …]) 
Plot computed optical mode field at threshold. 
plot_optical_field_horizontal ([resolution, …]) 
Plot horizontal distribution of the computed optical mode field at threshold. 
plot_optical_field_vertical ([pos, offset, …]) 
Plot vertical distribution of the computed optical mode field at threshold and refractive index profile. 
plot_temperature ([geometry_color, …]) 
Plot computed temperature to the current axes. 
plot_vert_optical_determinant (vneffs, **kwargs) 
Function plotting ‘vertical determinant’ of the optical solver. 
plot_vertical_voltage ([at]) 
Plot computed voltage along the vertical axis. 
plot_voltage ([geometry_color, mesh_color, …]) 
Plot computed voltage to the current axes. 
reconnect () 
Reconnect all internal solvers. 
save ([filename, group, optical_resolution]) 
Save the computation results to the HDF5 file. 
step (volt[, save]) 
Function performing one step of the threshold search. 
outCarriersConcentration 
Provider of the computed carriers concentration [1/cm³]. 
outConductivity 
Provider of the computed electrical conductivity [S/m]. 
outCurrentDensity 
Provider of the computed current density [kA/cm²]. 
outGain 
Provider of the computed material gain [1/cm]. 
outHeat 
Provider of the computed heat sources density [W/m³]. 
outHeatFlux 
Provider of the computed heat flux [W/m²]. 
outLightE 
Provider of the computed electric field [V/m]. 
outLightMagnitude 
Provider of the computed optical field magnitude [W/m²]. 
outLoss 
Provider of the computed modal extinction [1/cm]. 
outNeff 
Provider of the computed effective index []. 
outRefractiveIndex 
Provider of the computed refractive index []. 
outTemperature 
Provider of the computed temperature [K]. 
outThermalConductivity 
Provider of the computed thermal conductivity [W/(m×K)]. 
outVoltage 
Provider of the computed voltage [V]. 
diffusion 
electrical.diffusion.Diffusion2D solver used for electrical calculations. 
dneff 
Effective index step. 
electrical 
electrical.shockley.Shockley2D solver used for electrical calculations. 
gain 
gain.freecarrier.FreeCarrier2D solver used for gain calculations. 
id 
Id of the solver object. 
initialized 
True if the solver has been initialized. 
maxiter 
Maximum number of root finding iterations. 
mn 
Lateral mode number $n$. 
optical 
optical.effective.EffectiveIndex2D solver used for optical calculations. 
optical_resolution 
Number of points along the horizontal and vertical axes for the saved and plotted optical field. 
quick 

skip_thermal 
Skip thermal computations. 
tfreq 
Number of electrical iterations per single thermal step. 
thermal 
thermal.static.Static2D solver used for thermal calculations. 
vmax 
Maximum voltage to search threshold for. 
vmin 
Minimum voltage to search threshold for. 
vtol 
Tolerance on voltage in the root search. 
wavelength 
Emission wavelength [nm]. 
ThresholdSearch2D.
compute
(save=True, invalidate=False, group='ThresholdSearch', stepsave=False)¶Execute the algorithm.
In the beginning the solvers are invalidated and next, the self consistent loop of thermal, electrical, gain, and optical calculations are run within the rootfinding algorithm until the mode is found with zero optical losses.
Parameters: 


Returns:  The voltage set to >>> solver.get_total_current()
123.0

ThresholdSearch2D.
compute_thermoelectric
()¶Perform thermoelectric calculations.
This method may be called manually to perform thermoelectric calculations. Afterwards, one may investigate gain spectrum or verify settings of the optical solver.
ThresholdSearch2D.
get_gain_spectrum
(lams, pos=0.0, junction=0)¶Get gain spectrum for specified junction.
Parameters: 


Returns:  Gain spectrum. 
Return type: 
ThresholdSearch2D.
get_junction_concentrations
(interpolation='linear')¶Get carriers concentration at the active regions.
Parameters:  interpolation (str) – Interpolation used when retrieving current density. 

Returns: 

Return type:  dict 
ThresholdSearch2D.
get_junction_currents
(refine=16, interpolation='linear')¶Get current densities at the active regions.
Parameters: 


Returns: 

Return type:  dict 
ThresholdSearch2D.
get_junction_gains
(axis=None, interpolation='linear')¶Get gain at the active regions.
Parameters:  axis – Points along horizontal axis to plot gain at. Defaults to the optical mesh. 

Returns: 

Return type:  dict 
ThresholdSearch2D.
get_lam
()¶ThresholdSearch2D.
get_nng
()¶Get approximate effective index for optical computations.
This method returns approximate wavelength for optical computations.
By default if browses the wavelength range starting from maxneff
,
decreasing it by dneff
until lateral mode mn
is found.
You can override this method to use custom mode approximation.
Example
>>> solver = ThresholdSearch2D()
>>> solver.get_nng = lambda: 3.5
>>> solver.compute()
ThresholdSearch2D.
get_optical_determinant
(neff)¶Function computing determinant of the optical solver.
Parameters:  neff (float or array) – Effective index to compute the determinant for. 

Returns:  Optical determinant. 
Return type:  float or array 
ThresholdSearch2D.
get_optical_field
(resolution=None)¶Get computed optical mode field at threshold.
Parameters:  resolution (tuple of ints) – Number of points in horizontal and vertical directions. 

ThresholdSearch2D.
get_optical_field_horizontal
(resolution=None, interpolation='linear')¶Get horizontal distribution of the computed optical mode field at threshold.
Parameters: 


ThresholdSearch2D.
get_optical_field_vertical
(pos=0.01, offset=0.5, resolution=None, interpolation='linear')¶Plot vertical distribution of the computed optical mode field at threshold and refractive index profile.
Parameters: 


ThresholdSearch2D.
get_temperature
()¶Get temperature on a thermal mesh.
ThresholdSearch2D.
get_total_current
(nact=0)¶Get total current flowing through active region [mA]
ThresholdSearch2D.
get_vert_optical_determinant
(vneff)¶Function computing ‘vertical determinant’ of the optical solver.
Parameters:  vneff (float or array) – Effective index to compute the vertical determinant for. 

Returns:  Optical determinant. 
Return type:  float or array 
ThresholdSearch2D.
get_vertical_voltage
(at=0)¶Get computed voltage along the vertical axis.
Parameters:  at (float) – Horizontal position of the axis at which the voltage is plotted. 

ThresholdSearch2D.
get_voltage
()¶Get voltage on an electrical mesh.
ThresholdSearch2D.
initialize
()¶Initialize solver.
This method manually initialized the solver and sets initialized
to
True. Normally calling it is not necessary, as each solver automatically
initializes itself when needed.
Returns:  solver initialized state prior to this method call. 

Return type:  bool 
ThresholdSearch2D.
invalidate
()¶Set the solver back to uninitialized state.
This method frees the memory allocated by the solver and sets
initialized
to False.
ThresholdSearch2D.
plot_gain_spectrum
(lams, pos=0.0, junction=0, comp=None, **kwargs)¶Plot gain spectrum for specified junction.
Parameters: 


ThresholdSearch2D.
plot_junction_concentration
(bounds=True, interpolation='linear', label=None, **kwargs)¶Plot carriers concentration at the active region.
Parameters: 


ThresholdSearch2D.
plot_junction_current
(refine=16, bounds=True, interpolation='linear', label=None, **kwargs)¶Plot current density at the active region.
Parameters: 


ThresholdSearch2D.
plot_junction_gain
(axis=None, bounds=True, interpolation='linear', label=None, **kwargs)¶Plot gain at the active region.
Parameters: 


ThresholdSearch2D.
plot_optical_determinant
(neffs, **kwargs)¶Function plotting determinant of the optical solver.
Parameters: 


ThresholdSearch2D.
plot_optical_field
(resolution=None, geometry_color='0.75', geometry_alpha=0.35, **kwargs)¶Plot computed optical mode field at threshold.
Parameters: 


ThresholdSearch2D.
plot_optical_field_horizontal
(resolution=None, bounds=True, interpolation='linear', **kwargs)¶Plot horizontal distribution of the computed optical mode field at threshold.
Parameters: 


ThresholdSearch2D.
plot_optical_field_vertical
(pos=0.01, offset=0.5, resolution=None, interpolation='linear', **kwargs)¶Plot vertical distribution of the computed optical mode field at threshold and refractive index profile.
Parameters: 


ThresholdSearch2D.
plot_temperature
(geometry_color='0.75', mesh_color=None, geometry_alpha=0.35, mesh_alpha=0.15, **kwargs)¶Plot computed temperature to the current axes.
Parameters: 


See also
plask.plot_field()
: Plot any field obtained from receivers
ThresholdSearch2D.
plot_vert_optical_determinant
(vneffs, **kwargs)¶Function plotting ‘vertical determinant’ of the optical solver.
Parameters: 


ThresholdSearch2D.
plot_vertical_voltage
(at=0.0, **kwargs)¶Plot computed voltage along the vertical axis.
Parameters: 


ThresholdSearch2D.
plot_voltage
(geometry_color='0.75', mesh_color=None, geometry_alpha=0.35, mesh_alpha=0.15, **kwargs)¶Plot computed voltage to the current axes.
Parameters: 


See also
plask.plot_field()
: Plot any field obtained from receivers
ThresholdSearch2D.
reconnect
()¶Reconnect all internal solvers.
This method should be called if some of the internal solvers were changed manually.
ThresholdSearch2D.
save
(filename=None, group='ThresholdSearch', optical_resolution=None)¶Save the computation results to the HDF5 file.
Parameters: 


ThresholdSearch2D.
step
(volt, save=False)¶Function performing one step of the threshold search.
Parameters: 


Returns:  Loss of a specified mode 
Return type:  float 
ThresholdSearch2D.
outCarriersConcentration
(n=0, mesh, interpolation='default')¶Provider of the computed carriers concentration [1/cm³].
Parameters: 


Returns:  Data with the carriers concentration on the specified mesh [1/cm³]. 
You may obtain the number of different values this provider can return by testing its length.
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inCarriersConcentration = solver.outCarriersConcentration
Obtain the provided field:
>>> solver.outCarriersConcentration(0, mesh)
<plask.Data at 0x1234567>
Test the number of provided values:
>>> len(solver.outCarriersConcentration)
3
See also
Provider class: plask.flow.CarriersConcentrationProvider2D
Receciver class: plask.flow.CarriersConcentrationReceiver2D
ThresholdSearch2D.
outConductivity
(mesh, interpolation='default')¶Provider of the computed electrical conductivity [S/m].
Parameters: 


Returns:  Data with the electrical conductivity on the specified mesh [S/m]. 
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inConductivity = solver.outConductivity
Obtain the provided field:
>>> solver.outConductivity(mesh)
<plask.Data at 0x1234567>
See also
Provider class: plask.flow.ConductivityProvider2D
Receciver class: plask.flow.ConductivityReceiver2D
ThresholdSearch2D.
outCurrentDensity
(mesh, interpolation='default')¶Provider of the computed current density [kA/cm²].
Parameters: 


Returns:  Data with the current density on the specified mesh [kA/cm²]. 
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inCurrentDensity = solver.outCurrentDensity
Obtain the provided field:
>>> solver.outCurrentDensity(mesh)
<plask.Data at 0x1234567>
See also
Provider class: plask.flow.CurrentDensityProvider2D
Receciver class: plask.flow.CurrentDensityReceiver2D
ThresholdSearch2D.
outGain
(n=0, mesh, wavelength, interpolation='default')¶Provider of the computed material gain [1/cm].
Parameters: 


Returns:  Data with the material gain on the specified mesh [1/cm]. 
You may obtain the number of different values this provider can return by testing its length.
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inGain = solver.outGain
Obtain the provided field:
>>> solver.outGain(0, mesh, wavelength)
<plask.Data at 0x1234567>
Test the number of provided values:
>>> len(solver.outGain)
3
ThresholdSearch2D.
outHeat
(mesh, interpolation='default')¶Provider of the computed heat sources density [W/m³].
Parameters: 


Returns:  Data with the heat sources density on the specified mesh [W/m³]. 
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inHeat = solver.outHeat
Obtain the provided field:
>>> solver.outHeat(mesh)
<plask.Data at 0x1234567>
ThresholdSearch2D.
outHeatFlux
(mesh, interpolation='default')¶Provider of the computed heat flux [W/m²].
Parameters: 


Returns:  Data with the heat flux on the specified mesh [W/m²]. 
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inHeatFlux = solver.outHeatFlux
Obtain the provided field:
>>> solver.outHeatFlux(mesh)
<plask.Data at 0x1234567>
See also
Provider class: plask.flow.HeatFluxProvider2D
Receciver class: plask.flow.HeatFluxReceiver2D
ThresholdSearch2D.
outLightE
(n=0, mesh, interpolation='default')¶Provider of the computed electric field [V/m].
Parameters: 


Returns:  Data with the electric field on the specified mesh [V/m]. 
You may obtain the number of different values this provider can return by testing its length.
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inLightE = solver.outLightE
Obtain the provided field:
>>> solver.outLightE(0, mesh)
<plask.Data at 0x1234567>
Test the number of provided values:
>>> len(solver.outLightE)
3
ThresholdSearch2D.
outLightMagnitude
(n=0, mesh, interpolation='default')¶Provider of the computed optical field magnitude [W/m²].
Parameters: 


Returns:  Data with the optical field magnitude on the specified mesh [W/m²]. 
You may obtain the number of different values this provider can return by testing its length.
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inLightMagnitude = solver.outLightMagnitude
Obtain the provided field:
>>> solver.outLightMagnitude(0, mesh)
<plask.Data at 0x1234567>
Test the number of provided values:
>>> len(solver.outLightMagnitude)
3
See also
Provider class: plask.flow.LightMagnitudeProviderCyl
Receciver class: plask.flow.LightMagnitudeReceiverCyl
ThresholdSearch2D.
outLoss
(n=0)¶Provider of the computed modal extinction [1/cm].
Parameters:  n (int) – Value number. 

Returns:  Value of the modal extinction [1/cm]. 
You may obtain the number of different values this provider can return by testing its length.
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inModalLoss = solver.outLoss
Obtain the provided value:
>>> solver.outLoss(n=0)
1000
Test the number of provided values:
>>> len(solver.outLoss)
3
See also
Provider class: plask.flow.ModalLossProvider
Receciver class: plask.flow.ModalLossReceiver
ThresholdSearch2D.
outNeff
(n=0)¶Provider of the computed effective index [].
Parameters:  n (int) – Value number. 

Returns:  Value of the effective index []. 
You may obtain the number of different values this provider can return by testing its length.
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inEffectiveIndex = solver.outNeff
Obtain the provided value:
>>> solver.outNeff(n=0)
1000
Test the number of provided values:
>>> len(solver.outNeff)
3
See also
Provider class: plask.flow.EffectiveIndexProvider
Receciver class: plask.flow.EffectiveIndexReceiver
ThresholdSearch2D.
outRefractiveIndex
(mesh, interpolation='default')¶Provider of the computed refractive index [].
Parameters: 


Returns:  Data with the refractive index on the specified mesh []. 
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inRefractiveIndex = solver.outRefractiveIndex
Obtain the provided field:
>>> solver.outRefractiveIndex(mesh)
<plask.Data at 0x1234567>
See also
Provider class: plask.flow.RefractiveIndexProviderCyl
Receciver class: plask.flow.RefractiveIndexReceiverCyl
ThresholdSearch2D.
outTemperature
(mesh, interpolation='default')¶Provider of the computed temperature [K].
Parameters: 


Returns:  Data with the temperature on the specified mesh [K]. 
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inTemperature = solver.outTemperature
Obtain the provided field:
>>> solver.outTemperature(mesh)
<plask.Data at 0x1234567>
See also
Provider class: plask.flow.TemperatureProvider2D
Receciver class: plask.flow.TemperatureReceiver2D
ThresholdSearch2D.
outThermalConductivity
(mesh, interpolation='default')¶Provider of the computed thermal conductivity [W/(m×K)].
Parameters: 


Returns:  Data with the thermal conductivity on the specified mesh [W/(m×K)]. 
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inThermalConductivity = solver.outThermalConductivity
Obtain the provided field:
>>> solver.outThermalConductivity(mesh)
<plask.Data at 0x1234567>
See also
Provider class: plask.flow.ThermalConductivityProvider2D
Receciver class: plask.flow.ThermalConductivityReceiver2D
ThresholdSearch2D.
outVoltage
(mesh, interpolation='default')¶Provider of the computed voltage [V].
Parameters: 


Returns:  Data with the voltage on the specified mesh [V]. 
Example
Connect the provider to a receiver in some other solver:
>>> other_solver.inVoltage = solver.outVoltage
Obtain the provided field:
>>> solver.outVoltage(mesh)
<plask.Data at 0x1234567>
ThresholdSearch2D.
diffusion
= Diffusion2D()¶electrical.diffusion.Diffusion2D
solver used for electrical calculations.
ThresholdSearch2D.
dneff
= 0.02¶Effective index step.
Step, by which the effective index is swept while searching for the approximate mode.
ThresholdSearch2D.
electrical
= Shockley2D()¶electrical.shockley.Shockley2D
solver used for electrical calculations.
ThresholdSearch2D.
gain
= FreeCarrier2D()¶gain.freecarrier.FreeCarrier2D
solver used for gain calculations.
ThresholdSearch2D.
id
¶Id of the solver object. (read only)
Example
>>> mysolver.id
mysolver:category.type
ThresholdSearch2D.
initialized
¶True if the solver has been initialized. (read only)
Solvers usually get initialized at the beginning of the computations.
You can clean the initialization state and free the memory by calling
the invalidate()
method.
ThresholdSearch2D.
maxiter
= 50¶Maximum number of root finding iterations.
ThresholdSearch2D.
mn
= 1¶Lateral mode number $n$.
ThresholdSearch2D.
optical
= EffectiveIndex2D()¶optical.effective.EffectiveIndex2D
solver used for optical calculations.
ThresholdSearch2D.
optical_resolution
= (800, 600)¶Number of points along the horizontal and vertical axes for the saved and plotted optical field.
ThresholdSearch2D.
quick
= False¶ThresholdSearch2D.
skip_thermal
= False¶Skip thermal computations.
The structure is assumed to have a constant temperature. This can be used to look for the threshold under pulse laser operation.
ThresholdSearch2D.
tfreq
= 6.0¶Number of electrical iterations per single thermal step.
As temperature tends to converge faster, it is reasonable to repeat thermal solution less frequently.
ThresholdSearch2D.
thermal
= Static2D()¶thermal.static.Static2D
solver used for thermal calculations.
ThresholdSearch2D.
vmax
= None¶Maximum voltage to search threshold for.
It should be above the threshold.
ThresholdSearch2D.
vmin
= None¶Minimum voltage to search threshold for.
It should be below the threshold.
ThresholdSearch2D.
vtol
= 1e05¶Tolerance on voltage in the root search.
ThresholdSearch2D.
wavelength
= None¶Emission wavelength [nm].