Graphical User Interface Guide

The GUI starting program is defined in ErwinJr.py, which includes two tabs: the quantum tab and the optical tab. The quantum tab is mostly a GUI wrapper of QCLayers with a plotting canvas, while the optical tab is for OptStrata

Quantum Tab

../_images/qtab.png

A screenshot of the ErwinJr.py quantum tab.

The interface includes 4 columns:

settingBox

Description

Used as a comment, not for calculation

Substrate

Decide substrate, can influence strain and material set

E-field

Global electrical field

Position resolution

Finite-element grid size

Energy resolution

Scan size for the eigen-solver root finder.
It only shows when the ODE solver is selected.
This should be smaller than the smallest energy
difference.
If this is too small it’s possible to lose some states

No of States Per Period

Determines the number of states to solve for.
It only shows when the matrix solver is selected.
This should be large enough to cover the range of
interest

Repeats

Number of the whole structure

Wavelength

The wavelength is used for optimization and for calculating global gain

Basis Divisions

Defined for basis solver. See QCLayers.solve_basis()

Period info

Calculate the total length and doping density

layerBox

Layer Buttons

Insert above a layer or delete the selected layer

Optimize Buttons

Start optimizing.

  • Optimize Layer only optimize the selected layer on the selected FoM;

  • Global Optimize tries to optimize global gain.

  • The feature is experimental.

Layer Table

Show the table that defines the layer structure

solveBox

Solve basis button

Call QCLayers.solve_basis() and update plot

Solve whole button

Call QCLayers.solve_whole() and update plot

Material Table

Define the material used in the structure

Interface Roughness

The interface roughness \(\Delta\) and \(\Lambda\) See QCLayers.ifr_transition() for detail.

  • If Constant IFR is checked, all interfaces are having the same IFR parameters

  • If Constant IFR is not checked, IFR parameters are material dependent

  • The material BEFORE the interface determines the IFR

Plot control

  • Layer Select: select layer in Layer Table by clicking

  • Zoom: in with the right button of the mouse, out with the left

  • Pan: move with the mouse

  • Reset: make the plot back to the default position and scale

  • Clear: remove all wavefunctions

Calculation box

  • Pair Select: start to pick states by mouse

  • FoM: calculating full information of the picked state pair

  • Population: calculating the steady state electron population in percentage

  • ->Optics: transport parameters to the Active Core material in the Optical tab

  • Gain Spec: pop a new window showing the gain spectrum

The plot canvas

The black lines (or blue line if a well is selected) are the conduction band bottom of the potential. The states are the colored curve but thick black if selected. Other symmetry points in the band and the plot style of the wavefunctions can be changed from View in the menu bar. States that are thick in line are the selected set of a single period of states. This selected set is used to calculate the electron population distribution. States that are dashed lines are considered not well-bounded.

Export of the figure and data, save and load actions are embedded into File menu; temperature setting and advanced table settings are in Edit menu; options to choose what is included in the plot are listed in View menu.

Optics Tab

../_images/otab.png

A screenshot of the ErwinJr.py quantum tab.

The interface includes 3 columns:

settingBox

Wavelength

Can be transferred from quantum tab but not necessarily the same

Material Block

Defines the customized material. For pure GUI users, it defines Active Core transferred from quantum tab

  • index: the effective refractive index of the material

  • passive loss: the loss that’s not defined by gain below

  • Period Length and Periods: Determines the layer width of the Active core

Ridge Geometry

Defines the ridge facet loss for threshold gain calculation

  • Reflectivity depends on the effective refractive index, so the mirror loss will be updated after solved

strataBox

The Strata Table

Defines the waveguide structure.

  • At least an Active Core needs to be present.

  • The first and the last layers are environment and substrate that is not meant to be changed

Solving Block

Solve for the first bounded mode and show its character
The optimizing is performed for the lowest threshold, restricted to the total width of selected layers in the pop-up window.

The plot canvas

The black line and orange lines are the real and imaginary parts of the refractive index, respectively. The active core can be red based on the selection in View menu.