# PLaSK User Manual

#### Page Contents

- OldDiffusion2D Class
  - `OldDiffusion2D`
  - Methods
  - Attributes
    - Receivers
    - Providers
    - Other
  - Descriptions
    - Method Details
      - `OldDiffusion2D.compute_initial()`
      - `OldDiffusion2D.compute_overthreshold()`
      - `OldDiffusion2D.compute_threshold()`
      - `OldDiffusion2D.get_total_burning()`
      - `OldDiffusion2D.initialize()`
      - `OldDiffusion2D.invalidate()`
    - Receiver Details
      - `OldDiffusion2D.inCurrentDensity`
      - `OldDiffusion2D.inGain`
      - `OldDiffusion2D.inLightE`
      - `OldDiffusion2D.inTemperature`
    - Provider Details
      - `OldDiffusion2D.outCarriersConcentration`
    - Attribute Details
      - `OldDiffusion2D.abs_accuracy`
      - `OldDiffusion2D.accuracy`
      - `OldDiffusion2D.current_mesh`
      - `OldDiffusion2D.fem_method`
      - `OldDiffusion2D.geometry`
      - `OldDiffusion2D.id`
      - `OldDiffusion2D.initial`
      - `OldDiffusion2D.initialized`
      - `OldDiffusion2D.interpolation`
      - `OldDiffusion2D.maxiters`
      - `OldDiffusion2D.maxrefines`
      - `OldDiffusion2D.mesh`
      - `OldDiffusion2D.mode_burns`

# OldDiffusion2D Class

class electrical.olddiffusion.OldDiffusion2D(name='')

  Calculates carrier pairs concentration in active region using FEM in one-dimensional cartesian space

## Methods

`compute_initial`() | Perform the initial computation
`compute_overthreshold`() | Perform the overthreshold computation
`compute_threshold`() | Perform the threshold computation
`get_total_burning`() | Compute total power burned over threshold (mW).
`initialize`() | Initialize solver.
`invalidate`() | Set the solver back to uninitialized state.

## Attributes

### Receivers

`inCurrentDensity` | Receiver of the current density required for computations [kA/cm²].
`inGain` | Receiver of the material gain required for computations [1/cm].
`inLightE` | Receiver of the electric field required for computations [V/m].
`inTemperature` | Receiver of the temperature required for computations [K].

### Providers

`outCarriersConcentration` | Provider of the computed carriers concentration [1/cm³].

### Other

`abs_accuracy` | Required absolute minimal concentration accuracy
`accuracy` | Required relative accuracy
`current_mesh` | Horizontal adaptive mesh)
`fem_method` | Finite-element method (linear of parabolic)
`geometry` | Geometry provided to the solver
`id` | Id of the solver object.
`initial` | True if we start from initial computations
`initialized` | True if the solver has been initialized.
`interpolation` | Interpolation method used for injection current
`maxiters` | Maximum number of allowed iterations before attempting to refine mesh
`maxrefines` | Maximum number of allowed mesh refinements
`mesh` | Mesh provided to the solver
`mode_burns` | Power burned over threshold by each mode (mW).

## Descriptions

### Method Details

OldDiffusion2D.compute_initial()

  Perform the initial computation

OldDiffusion2D.compute_overthreshold()

  Perform the overthreshold computation

OldDiffusion2D.compute_threshold()

  Perform the threshold computation

OldDiffusion2D.get_total_burning()

  Compute total power burned over threshold (mW).

OldDiffusion2D.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

OldDiffusion2D.invalidate()

  Set the solver back to uninitialized state.

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

### Receiver Details

OldDiffusion2D.inCurrentDensity = <property object>

  Receiver of the current density required for computations [kA/cm²].

  You will find usage details in the documentation of the receiver class `CurrentDensityReceiver2D`.

  Example

  Connect the receiver to a provider from some other solver:

      >>> solver.inCurrentDensity = other_solver.outCurrentDensity

  See also

  Receciver class: `plask.flow.CurrentDensityReceiver2D`

  Provider class: `plask.flow.CurrentDensityProvider2D`

  Data filter: `plask.filter.CurrentDensityFilter2D`

OldDiffusion2D.inGain = <property object>

  Receiver of the material gain required for computations [1/cm]. It is required only for the overthreshold computations.

  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`

OldDiffusion2D.inLightE = <property object>

  Receiver of the electric field required for computations [V/m]. It is required only for the overthreshold computations.

  You will find usage details in the documentation of the receiver class `ModeLightEReceiver2D`.

  Example

  Connect the receiver to a provider from some other solver:

      >>> solver.inLightE = other_solver.outModeLightE

  See also

  Receciver class: `plask.flow.ModeLightEReceiver2D`

  Provider class: `plask.flow.ModeLightEProvider2D`

  Data filter: `plask.filter.ModeLightEFilter2D`

OldDiffusion2D.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

OldDiffusion2D.outCarriersConcentration(n=0, mesh, interpolation='default') = <property object>

  Provider of the computed carriers concentration [1/cm³].

  Parameters:

    - type (str) – Detailed information which carriers are returned. It can be ‘majority’ to return majority carriers in given material, ‘pairs’ for the concentration of electron-hole pairs, ‘electrons’, or ‘holes’ for particular carriers type.

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

    - interpolation (str) – Requested interpolation method.

  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`

### Attribute Details

OldDiffusion2D.abs_accuracy = <property object>

  Required absolute minimal concentration accuracy

OldDiffusion2D.accuracy = <property object>

  Required relative accuracy

OldDiffusion2D.current_mesh = <property object>

  Horizontal adaptive mesh)

OldDiffusion2D.fem_method = <property object>

  Finite-element method (linear of parabolic)

OldDiffusion2D.geometry = <property object>

  Geometry provided to the solver

OldDiffusion2D.id = <property object>

  Id of the solver object. (read only)

  Example

      >>> mysolver.id
      mysolver:category.type

OldDiffusion2D.initial = <property object>

  True if we start from initial computations

OldDiffusion2D.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.

OldDiffusion2D.interpolation = <property object>

  Interpolation method used for injection current

OldDiffusion2D.maxiters = <property object>

  Maximum number of allowed iterations before attempting to refine mesh

OldDiffusion2D.maxrefines = <property object>

  Maximum number of allowed mesh refinements

OldDiffusion2D.mesh = <property object>

  Mesh provided to the solver

OldDiffusion2D.mode_burns = <property object>

  Power burned over threshold by each mode (mW).