OSS : Organic Systems Simulator

Terminal based application to study the energy state population dynamics of organic semiconductor lasers.

Tables of contents

1. Introduction
2. Copyright and license
3. Recommended tools
4. Required modules
5. Install missing libraries
6. Obtain the source code
7. Run simulations
8. Useful ressources
9. Roadmap

Introduction

The OSS code can be used to simulate the dynamics of the energy states populations of organic molecules in thin films. The populations can be integrated with or without a resonator via an equation governing the photon density inside it. Moreover, an algorithm is implemented to evaluate the lasing regime in precise photophysical and optical configurations.

The details concerning the core of the equations and the different algorithms used in OSS are extensively discussed in the white sheet of the project and in the cited published papers.

The project folder is structured as follows:

• src : python scripts to run the proram
• refs : example of the output datas processed by the program for each available simulation.
• doc : whitesheet of the project and scientifics references to look over. (not published yet)

Copyright and license

The OSS project is licensed under the GNU General Public License version 3. The details of this license can be found in the file LICENSE.md.

Recommended tools

• Git
• A text editor (e.g. VS code) or a Python IDE (e.g. Spyder)

Required modules

• Python 3.X
• numpy >= 1.21.2
• matplotlib >= 3.3.3
• scipy >= 1.6.0
• platform >= 2.0.2
• os

NOTE : If you use an integrated developement environement, you should not be concerned by the lake of libraries on your computer.

Although basic modules are pre-installed in most Linux distributions or in MacOS, specific ones sometimes require manual installation. To check if the module example is installed on your computer, run the following command on a terminal:

cd /usr/lib/python3.X/site-packages/
ls -l | grep <example>

where X is your current version of python, obtained by the command python --version.

Install missing libraries

1. Install pip

PIP is a terminal tool used to ease the installation of external packages or libraries. If you want more details, look over the documentation. There are two main ways to install it on your computer. You can either download this python script and execute it by running these command in a terminal:

cd path/to/get-pip.py
python get-pip.py

or install it from your package manager.

sudo apt update 
sudo apt install python3-pip

2. Install some libraries

To install the Python module example, run this command from anywhere on a terminal:

pip install --m <example> 

It is recommended to check afterwards that the module is installed correctly in your system.

pip freeze | grep <example>

Obtain the source code

You can download it on the main page or clone it via the following commands. This will automatically create a folder oss containing each files and folders of the project.

cd path/to/your/work/folder
git clone https://github.com/dllagl/oss.git

Run simulations

1. Execute OSS source code

Once you are in the 'oss' folder and you have the required libraries you can execute the OSS code.

cd src
python main.py 

This will automatically create a folder name after what you enter in the terminal prompt (output by default) which will contain :

• data.out which contains the output datas (time, populations ..)
• data.params which contains the configuration of the simulation (date, computer's infos and contants)

Examples of those files can be found in the refs folder for each available simulation.

2. Run it your way

For the simpliest simulations options, the only interactions you need to have with the code is to change the values of the photophysical and optical constants in imp_param.py. The prompt will guide you for other options.

3. Read the output files

Python scripts can be found alongside examples data files to guide Python beginners to plot the results of their simulations. Since datas are written in text files, they can be processed in any language anyway.

Useful ressources

1. Scientific papers

Here are some peer-reviewed scientific papers, Ph.D. thesis or books that work with the system of equations implemented in OSS :

• [1] C. Gärtner, C. Karnutsch, U. Lemmer and C. Pflumm, Journal of Applied Physics, 2007, 101, 023107
• [2] S. Forget and S. Chénais, Organic solid-state lasers, Springer, Heidelberg, 2013.
• [3] F. Bencheikh, A. S. D. Sandanayaka, T. Fukunaga, T. Mat- sushima and C. Adachi, Journal of Applied Physics, 2019, 126, 185501.

2. Instructional videos (ongoing production)

Roadmap

• Write complete documentation
• Tutorial videos
• Parallelize lasing regime computation
• Add an option to iterate over two variables at once for the lasing regime study
• Add different cavities