MiePy

MiePy is a Python module for the generalized multiparticle Mie theory (GMMT), also known as the aggregate T-matrix method. MiePy solves the electrodynamics of a collection of spherical or non-spherical scatterers with an arbitrary incident source.

<p align="center"> <img src="./docs/miepy_thumbnail.png" width="500" alt="Electric field visualization"> <br> <em>Electric field around a 37 particle cluster</em> </p> <p align="center"> <img src="https://jparker.nyc3.digitaloceanspaces.com/gallery/em_three_np_contours.png" width="500" alt="Three particle system"> <br> <em>3D electric field contours around three metal nanoparticles</em> </p>

Features

• Non-spherical particles using the T-matrix formulation via the extended boundary condition method (EBCM). Includes cylinders, spheroids, ellipsoids, cubes and polygonal prisms
• Arbitrary incident sources (plane waves, Gaussian beams, HG and LG beams, point dipoles)
• Evaluation of cluster cross-sections and optical force and torque on individual particles
• Periodic boundary conditions with various lattice types (square, hexagonal, etc.) and mirror and discrete rotational symmetries for faster calculations
• Optional planar interface (substrate)
• 3D scene visualization using the VPython library
• Image clusters using a simulated microscope
• OpenMP parallelization for systems with larger numbers of particles

Installation

pip install miepy

If using uv:

uv venv --python 3.13
uv pip install miepy
source .venv/bin/activate

GPU Backend (optional)

To use the GPU-accelerated solver backend:

pip install miepy[gpu]

Then activate the GPU backend:

import miepy
miepy.backends.set_backend('gpu')

Usage

See the examples folder for how to use MiePy.

Run any of the available examples without explicit installation using uv:

| Command | Description | |---------|-------------| | uvx miepy dielectric_sphere | Dielectric sphere scattering and cross-sections | | uvx miepy ag_sphere | Silver sphere scattering and absorption | | uvx miepy ag_shell | Core-shell particle scattering | | uvx miepy vary_index | Scattering intensity vs wavelength and refractive index | | uvx miepy fields | Electric and magnetic field visualization | | uvx miepy dimer_scattering | Au dimer cross-sections | | uvx miepy dimer_force | Force and torque on dimer particles | | uvx miepy far_field | Far-field radiation patterns | | uvx miepy whispering_gallery | Whispering gallery modes in dielectric sphere | | uvx miepy focused_gaussian | Focused Gaussian beam with orbital angular momentum | | uvx miepy imaging | Near-field, far-field, and microscope imaging |

For an overview of the theory, see docs folder.

Install from source

MiePy uses vcpkg for C++ dependency management and uv for Python management, which simplifies building across platforms.

Prerequisites:

• GCC
• uv

Build steps:

1. Clone MiePy and its submodules:

git clone https://github.com/johnaparker/miepy.git miepy --recurse-submodules && cd miepy

2. Bootstrap vcpkg (first time only):

./vcpkg/bootstrap-vcpkg.sh

3. Install MiePy using uv:

uv sync

4. Optionally, run the tests to verify correctness:

uv run pytest tests

License

MiePy is licensed under the terms of the GPLv3 license.