# PLaSK User Manual

#### Page Contents

- EffectiveIndex2D Class
  - `EffectiveIndex2D`
  - Subclasses
  - Methods
  - Attributes
    - Receivers
    - Providers
    - Other
  - Descriptions
    - Method Details
      - `EffectiveIndex2D.clear_modes()`
      - `EffectiveIndex2D.find_mode()`
      - `EffectiveIndex2D.find_modes()`
      - `EffectiveIndex2D.get_delta_neff()`
      - `EffectiveIndex2D.get_determinant()`
      - `EffectiveIndex2D.get_total_absorption()`
      - `EffectiveIndex2D.get_vert_determinant()`
      - `EffectiveIndex2D.initialize()`
      - `EffectiveIndex2D.invalidate()`
      - `EffectiveIndex2D.search_vneff()`
      - `EffectiveIndex2D.set_mode()`
      - `EffectiveIndex2D.set_simple_mesh()`
    - Receiver Details
      - `EffectiveIndex2D.inCarriersConcentration`
      - `EffectiveIndex2D.inGain`
      - `EffectiveIndex2D.inTemperature`
    - Provider Details
      - `EffectiveIndex2D.outElectricField`
      - `EffectiveIndex2D.outHeat`
      - `EffectiveIndex2D.outLightE`
      - `EffectiveIndex2D.outLightMagnitude`
      - `EffectiveIndex2D.outNeff`
      - `EffectiveIndex2D.outRefractiveIndex`
    - Attribute Details
      - `EffectiveIndex2D.emission`
      - `EffectiveIndex2D.geometry`
      - `EffectiveIndex2D.id`
      - `EffectiveIndex2D.initialized`
      - `EffectiveIndex2D.mesh`
      - `EffectiveIndex2D.mirrors`
      - `EffectiveIndex2D.modes`
      - `EffectiveIndex2D.polarization`
      - `EffectiveIndex2D.root`
      - `EffectiveIndex2D.stripe_root`
      - `EffectiveIndex2D.vat`
      - `EffectiveIndex2D.vneff`
      - `EffectiveIndex2D.wavelength`

# EffectiveIndex2D Class

class optical.effective.EffectiveIndex2D(name='')

  Calculate optical modes and optical field distribution using the effective index method in two-dimensional Cartesian space.

## Subclasses

`Mode` | Detailed information about the mode.

## Methods

`clear_modes`() | Clear all computed modes.
`find_mode`(neff[, symmetry]) | Compute the mode near the specified effective index.
`find_modes`([start, end, symmetry, resteps, ...]) | Find the modes within the specified range using global method.
`get_delta_neff`(pos) | Return effective index part for lateral propagation at specified horizontal position.
`get_determinant`(neff) | Get modal determinant.
`get_total_absorption`([num]) | Get total energy absorbed by from a mode in unit time.
`get_vert_determinant`(neff) | Get vertical modal determinant for debugging purposes.
`initialize`() | Initialize solver.
`invalidate`() | Set the solver back to uninitialized state.
`search_vneff`([start, end, resteps, imsteps, eps]) | Find the effective indices in the vertical direction within the specified range using global method.
`set_mode`(arg2[, symmetry]) | Set the current mode the specified effective index.
`set_simple_mesh`() | Set simple mesh based on the geometry objects bounding boxes.

## Attributes

### Receivers

`inCarriersConcentration` | Receiver of the carriers concentration required for computations [1/cm³].
`inGain` | Receiver of the material gain required for computations [1/cm].
`inTemperature` | Receiver of the temperature required for computations [K].

### Providers

`outElectricField` | Alias for `outLightE`.
`outHeat` | Provider of the computed heat sources density [W/m³].
`outLightE` | Provider of the computed electric field [V/m].
`outLightMagnitude` | Provider of the computed optical field magnitude [W/m²].
`outNeff` | Provider of the computed effective index [-].
`outRefractiveIndex` | Provider of the computed refractive index [-].

### Other

`emission` | Emission direction.
`geometry` | Geometry provided to the solver
`id` | Id of the solver object.
`initialized` | True if the solver has been initialized.
`mesh` | Mesh provided to the solver.
`mirrors` | Mirror reflectivities.
`modes` | List of the computed modes.
`polarization` | Polarization of the searched modes.
`root` | Configuration of the root searching algorithm for horizontal component of the mode.
`stripe_root` | Configuration of the root searching algorithm for vertical component of the mode in a single stripe.
`vat` | Horizontal position of the main stripe (with dominant mode).
`vneff` | Effective index in the vertical direction.
`wavelength` | Current wavelength.

## Descriptions

### Method Details

EffectiveIndex2D.clear_modes()

  Clear all computed modes.

EffectiveIndex2D.find_mode(neff, symmetry=None)

  Compute the mode near the specified effective index.

  Parameters:

    - neff (complex) – Starting point of the root search.

    - symmetry ('+' or '-') – Symmetry of the mode to search. If this parameter is not specified, the default symmetry is used: positive mode symmetry fir symmetrical geometries and no symmetry for asymmetrical geometries.

  Returns:

    Index in the `modes` list of the found mode.

  Return type:

    integer

EffectiveIndex2D.find_modes(start=0.0, end=0.0, symmetry=None, resteps=256, imsteps=64, eps=1e-06 + 1e-09j)

  Find the modes within the specified range using global method.

  Parameters:

    - start (complex) – Start of the search range (0 means automatic).

    - end (complex) – End of the search range (0 means automatic).

    - resteps (integer) – Number of steps on the real axis during the search.

    - imsteps (integer) – Number of steps on the imaginary axis during the search.

    - eps (complex) – required precision of the search.

  Returns:

    List of the indices in the `modes` list of the found modes.

  Return type:

    list of integers

EffectiveIndex2D.get_delta_neff(pos)

  Return effective index part for lateral propagation at specified horizontal position.

  Parameters:

    pos (float or array of floats) – Horizontal position to get the effective index.

EffectiveIndex2D.get_determinant(neff)

  Get modal determinant.

  Parameters:

    - neff (complex or array of complex) – effective index value

    - at. (to compute the determinant) –

  Returns:

    Determinant at the effective index neff or an array matching its size.

  Return type:

    complex or list of complex

EffectiveIndex2D.get_total_absorption(num=0)

  Get total energy absorbed by from a mode in unit time.

  Parameters:

    num (int) – number of the mode.

  Returns:

    Total absorbed energy (mW).

EffectiveIndex2D.get_vert_determinant(neff)

  Get vertical modal determinant for debugging purposes.

  Parameters:

    - neff (complex of numeric array of complex) – Vertical effective index value

    - at. (to compute the determinant) –

  Returns:

    Determinant at the vertical effective index neff or an array matching its size.

  Return type:

    complex or list of complex

EffectiveIndex2D.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

EffectiveIndex2D.invalidate()

  Set the solver back to uninitialized state.

  This method frees the memory allocated by the solver and sets `initialized` to False.

EffectiveIndex2D.search_vneff(start=0.0, end=0.0, resteps=256, imsteps=64, eps=1e-06 + 1e-09j)

  Find the effective indices in the vertical direction within the specified range using global method.

  Parameters:

    - start (complex) – Start of the search range (0 means automatic).

    - end (complex) – End of the search range (0 means automatic).

    - resteps (integer) – Number of steps on the real axis during the search.

    - imsteps (integer) – Number of steps on the imaginary axis during the search.

    - eps (complex) – required precision of the search.

  Returns:

    List of the found effective indices in the vertical direction.

  Return type:

    list of floats

EffectiveIndex2D.set_mode(arg2, symmetry=None)

  Set the current mode the specified effective index.

  Parameters:

    - neff (complex) – Mode effective index.

    - symmetry ('+' or '-') – Symmetry of the mode to search.

EffectiveIndex2D.set_simple_mesh()

  Set simple mesh based on the geometry objects bounding boxes.

### Receiver Details

EffectiveIndex2D.inCarriersConcentration = <property object>

  Receiver of the carriers concentration required for computations [1/cm³].

  You will find usage details in the documentation of the receiver class `CarriersConcentrationReceiver2D`.

  Example

  Connect the receiver to a provider from some other solver:

      >>> solver.inCarriersConcentration = other_solver.outCarriersConcentration

  See also

  Receciver class: `plask.flow.CarriersConcentrationReceiver2D`

  Provider class: `plask.flow.CarriersConcentrationProvider2D`

  Data filter: `plask.filter.CarriersConcentrationFilter2D`

EffectiveIndex2D.inGain = <property object>

  Receiver of the material gain required for computations [1/cm].

  You will find usage details in the documentation of the receiver class `GainReceiver2D`.

  Example

  Connect the receiver to a provider from some other solver:

      >>> solver.inGain = other_solver.outGain

  See also

  Receciver class: `plask.flow.GainReceiver2D`

  Provider class: `plask.flow.GainProvider2D`

  Data filter: `plask.filter.GainFilter2D`

EffectiveIndex2D.inTemperature = <property object>

  Receiver of the temperature required for computations [K].

  You will find usage details in the documentation of the receiver class `TemperatureReceiver2D`.

  Example

  Connect the receiver to a provider from some other solver:

      >>> solver.inTemperature = other_solver.outTemperature

  See also

  Receciver class: `plask.flow.TemperatureReceiver2D`

  Provider class: `plask.flow.TemperatureProvider2D`

  Data filter: `plask.filter.TemperatureFilter2D`

### Provider Details

EffectiveIndex2D.outElectricField = <property object>

  Alias for `outLightE`.

EffectiveIndex2D.outHeat(mesh, interpolation='default') = <property object>

  Provider of the computed heat sources density [W/m³].

  Parameters:

    - mesh (mesh) – Target mesh to get the field at.

    - interpolation (str) – Requested interpolation method.

  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>

  See also

  Provider class: `plask.flow.HeatProvider2D`

  Receciver class: `plask.flow.HeatReceiver2D`

EffectiveIndex2D.outLightE(n=0, mesh, interpolation='default') = <property object>

  Provider of the computed electric field [V/m].

  Parameters:

    - n (int) – Number of the mode found with `find_mode()`.

    - mesh (mesh) – Target mesh to get the field at.

    - interpolation (str) – Requested interpolation method.

  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.inModeLightE = solver.outLightE

  Obtain the provided field:

      >>> solver.outLightE(0, mesh)
      <plask.Data at 0x1234567>

  Test the number of provided values:

      >>> len(solver.outLightE)
      3

  See also

  Provider class: `plask.flow.ModeLightEProvider2D`

  Receciver class: `plask.flow.ModeLightEReceiver2D`

EffectiveIndex2D.outLightMagnitude(n=0, mesh, interpolation='default') = <property object>

  Provider of the computed optical field magnitude [W/m²].

  Parameters:

    - n (int) – Number of the mode found with `find_mode()`.

    - mesh (mesh) – Target mesh to get the field at.

    - interpolation (str) – Requested interpolation method.

  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.inModeLightMagnitude = 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.ModeLightMagnitudeProvider2D`

  Receciver class: `plask.flow.ModeLightMagnitudeReceiver2D`

EffectiveIndex2D.outNeff(n=0) = <property object>

  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.inModeEffectiveIndex = 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.ModeEffectiveIndexProvider`

  Receciver class: `plask.flow.ModeEffectiveIndexReceiver`

EffectiveIndex2D.outRefractiveIndex(n=0, mesh, lam=DEFAULT, interpolation='default') = <property object>

  Provider of the computed refractive index [-].

  Parameters:

    - comp (str) – Component of a diagonal refractive index derivative to return. Can be ‘ll’, ‘tt’, ‘vv’, or equivalent using current axes names. For scalar solvers this argument is ignored and can be skipped.

    - mesh (mesh) – Target mesh to get the field at.

    - interpolation (str) – Requested interpolation method.

    - lam (float) – Complex wavelength at which the refractive index is computed (nm).

  Returns:

    Data with the refractive index on the specified mesh [-].

  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.inRefractiveIndex = solver.outRefractiveIndex

  Obtain the provided field:

      >>> solver.outRefractiveIndex(0, mesh, lam=DEFAULT)
      <plask.Data at 0x1234567>

  Test the number of provided values:

      >>> len(solver.outRefractiveIndex)
      3

  See also

  Provider class: `plask.flow.RefractiveIndexProvider2D`

  Receciver class: `plask.flow.RefractiveIndexReceiver2D`

### Attribute Details

EffectiveIndex2D.emission = <property object>

  Emission direction.

EffectiveIndex2D.geometry = <property object>

  Geometry provided to the solver

EffectiveIndex2D.id = <property object>

  Id of the solver object. (read only)

  Example

      >>> mysolver.id
      mysolver:category.type

EffectiveIndex2D.initialized = <property object>

  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.

EffectiveIndex2D.mesh = <property object>

  Mesh provided to the solver.

EffectiveIndex2D.mirrors = <property object>

  Mirror reflectivities. If None then they are automatically estimated from theFresnel equations.

EffectiveIndex2D.modes = <property object>

  List of the computed modes.

  Item Attributes

  `neff` | Mode effective index.
  `symmetry` | Mode symmetry ('positive', 'negative', or None).
  `power` | Total power emitted into the mode (mW).
  `total_absorption` | Cumulated absorption for the mode (mW).

  Return type:

    optical.effecticve.EffectiveIndex2D.Mode

EffectiveIndex2D.polarization = <property object>

  Polarization of the searched modes.

EffectiveIndex2D.root = <property object>

  Configuration of the root searching algorithm for horizontal component of the mode.

  Attributes:

  `alpha` | Parameter ensuring sufficient decrease of determinant in each step (Broyden method only).
  `lambd` | Minimum decrease ratio of one step (Broyden method only).
  `initial_range` | Initial range size (Muller and Brent methods only).
  `maxiter` | Maximum number of iterations.
  `maxstep` | Maximum step in one iteration (Broyden method only).
  `method` | Root finding method ('muller', 'broyden', or 'brent')
  `tolf_max` | Required tolerance on the function value.
  `tolf_min` | Sufficient tolerance on the function value.
  `tolx` | Absolute tolerance on the argument.
  `stairs` | Number of staircase iterations (Brent method only).

  Return type:

    RootParams

EffectiveIndex2D.stripe_root = <property object>

  Configuration of the root searching algorithm for vertical component of the mode in a single stripe.

  Attributes:

  `alpha` | Parameter ensuring sufficient decrease of determinant in each step (Broyden method only).
  `lambd` | Minimum decrease ratio of one step (Broyden method only).
  `initial_range` | Initial range size (Muller and Brent methods only).
  `maxiter` | Maximum number of iterations.
  `maxstep` | Maximum step in one iteration (Broyden method only).
  `method` | Root finding method ('muller', 'broyden', or 'brent')
  `tolf_max` | Required tolerance on the function value.
  `tolf_min` | Sufficient tolerance on the function value.
  `tolx` | Absolute tolerance on the argument.
  `stairs` | Number of staircase iterations (Brent method only).

  Return type:

    RootParams

EffectiveIndex2D.vat = <property object>

  Horizontal position of the main stripe (with dominant mode).

EffectiveIndex2D.vneff = <property object>

  Effective index in the vertical direction.

EffectiveIndex2D.wavelength = <property object>

  Current wavelength.